Do you like time travel and sci-fi stories?


Then you should keep reading, because we had the honor of interviewing the authors of the exciting time travel series, Vivy: Fluorite Eye’s Song: Tappei Nagatsuki and Eiji Umehara.


If you didn’t know, Nagatsuki-sensei is also the author of Re:ZERO -Starting Life in Another World, and has been involved with other series like Isekai Quartet and ​​Senyoku no Sigrdrifa. Meanwhile, Umehara-sensei has been involved in series like Chaos;Child, Grimoire of Zero, etc.


So, let’s start the interview!


Note: This interview has been edited for clarity.


Mipon: What are the difficulties involved when writing a time-travel story?


Nagatsuki: The foundation of your typical time-travel story is that there’s a past that’s “flawed” or “incorrect,” and so the goal is to fix that past. You have to create two different worlds, or timelines, and think about what’s wrong with Timeline A and how it should be in Timeline B. Basically, one story becomes two. So, there’s a lot more planning and preparation to do compared with linear storylines, which can be tiring.



M: I see, that does sound difficult.


Umehara: Nagatsuki-san has a lot of experience with this kind of thing, so he was truly a godsend in that respect.


N: Yeah, I’m good at repeating the same events over and over and over (laughs).



M: I’m a big fan of time-travel stories, so I really enjoyed Vivy.


U: I’m glad to hear that.


M: Nagatsuki-san, how did you come to be involved in the project?


N: I was invited by Umehara-san.


U: I was part of the scriptwriting team for the anime adaptation of Nagatsuki-san’s Re:Zero − Starting Life in Another World. After reading the light novels and speaking with Nagatsuki-san during meetings, I felt we got on quite well together and that it’d be fun to team up and work on something. So, I brought up the idea with him, and that’s how we got the ball rolling. 



M: Ah, so that’s how it all began. Did you meet during work on the Re:Zero anime?


N: Yeah, we met face-to-face while working on Re:Zero, but I’d first heard about Umehara-san through a video game I had recently played. It was a really interesting game, and I thought to myself. “Man, that was great! Who wrote the story”? And listed in the credits as a head writer was Umehara-san, so I made a point to remember his name. The very next day, we were having a meeting about scriptwriting for the second cour of Re:Zero, and the writer,


[Masahiro] Yokotani-san said he wanted to add another writer to the team. The name “Eiji Umehara” came up as we were deciding who to ask, and I said, “Wait a minute…I swear I just heard that name recently…” (laughs) “Oh yeah, from that awesome game I just finished! If it’s possible, we should definitely ask him!”


So, he joined the team, and the very first thing I said to him was, “That game’s writing was purely devilish!” (laughs)



U: You don’t forget hearing something like that from someone you just met (laughs).


N: I said: “It was so good! There’s no way a normal person could come up with that!” 


U: He’s referring to a game that I worked on as a scenario writer and was published by MAGES., the creators of Steins;Gate.


N: That was our first-time meeting in person, but I was already familiar with his work at the time. So, I felt at ease being able to work with him.



M: What was the scenario writing process like? Did working as a pair lead to any disagreements or conflicts? And if so, how did you resolve them?


N: I indirectly touched on this a bit earlier, but we really got on well and didn’t fight over anything.


U: Of course, that’s not to say there weren’t differences of opinion. We had plenty of disagreements, but rather than deteriorating into arguments, we’d go back and forth with our opinions. It was mostly along the lines of: “OK, but what if we wrote it this way instead?”



N: Yeah, we never flipped out and screamed at each other. We tried to keep it constructive. If we did come to an impasse, we’d just pack it in and say, “Alright, let’s discuss this next week then.”


But I think that’s quite uncommon. Normally, if you put two creators together, they’re liable to get into heated arguments.


M: That’s a relief. I’m glad you two never fought like that.


N: We’d exchange opinions and discuss lots of things, but never any arguing or fighting.


M: And that’s how you ended up with such a great story!


U: That’s very kind of you to say.



M: How did your prior work experience influence the setting and story of Vivy?


N: I hadn’t really been all that involved with anime production anyway, which makes it hard for me to answer. Honestly, I don’t think I have an answer (laughs). I just figured, “Well, if Umehara-san’s here, everything will be fine”! During production, I put my trust completely into his experience with Re:Zero.


[To Umehara] Maybe you can answer this one better.



U: Nagatsuki-san may say that, but he contributed a lot to meetings when we were writing Re:Zero. Although he was originally the writer of the original light novel, he was very involved in the scriptwriting and visual production aspects and gave a lot of helpful feedback. I’d say he contributed the most to those meetings.


For example, he’d say, “Let’s cut out this part. In terms of visuals, it isn’t very interesting”. That’s quite rare for original creators to be so upfront. Of course, most creators [of the original work] will say things like, “No, no, please be faithful to the novel”, and so on.


But Nagatsuki-san was eager to share his opinions and make it a great visual work. He was a huge help not only to me but also to everyone else on the scriptwriting team including Yokotani-san and [Yoshiko] Nakamura-san. Our meetings were really productive thanks to his help.



M: Like Vivy, Re:Zero also involves time travel. How did your experience with writing Re:Zero help you when writing Vivy’s story?


N: This isn’t strictly related to time travel plots, but one thing Re:Zero and Vivy have in common is that people seem to keep enjoying it no matter how distressing the story becomes (laughs). Re:Zero in particular just gets more and more depressing, with a brief moment of hope. I was worried that might put everyone off, but it seemed to work out.


So, I thought, “Maybe Vivy can have depressing story arcs over and over too”! Looking back, there were a lot of those in Vivy (laughs).



M: So, the ability to create those kinds of stories was very helpful.


N: Yeah, we made the most of our experience. That said, Vivy isn’t about repeating the same events over and over—it’s mostly a series of different struggles. The idea is that we know what’s going to happen, but we don’t know how things ended up that way. That lack of information lends an air of mystery to the plot.


So, we used our experience from Re:Zero to include story elements that help viewers piece together the truth, as well as other ways to capture attention. Going against the flow of time is one type of time travel, so I tried to make the most of my experience in that regard.




M: How about you, Umehara-san?


U: Well, as I mentioned earlier, I mainly deferred to Nagatsuki-san because he had so much more experience with time travel and looping stories. In that respect, at least, I felt that since he did such a great job with Re:Zero, we’d definitely come up with something great if we let him handle the time travel aspects. 


Story elements like AI and music were suggested by the producer from the beginning, but it was Nagatsuki-san who suggested we do a story about time travel and rewriting history.



M: One of my favorite things about Vivy is its message. To many fans and I, the message is one of: “Finding your own reason to live freely”. How do you feel about that interpretation?


N: If you’re asking what my reason for living is, it’s to create stories that really have an effect on people’s lives (laughs). I mean like destroying the will of any other creators besides myself (laughs). Lots of people are fascinated by an amazing novel, manga or whatever and decide to become creators themselves. I’m definitely one of those people.


But what I want to do is create something so amazing that other would-be creators lose hope of ever reaching that level and give up (laughs).


U: Whoa, that’s brutal! (laughs)


M: Very cool! (laughs)


N: Thank you



M: How about you, Umehara-san? What are your thoughts on Vivy’s message?


U: Of course, as a creator, I’d say my answer is closer to Nagatsuki-san’s. I want to write stuff that changes people’s lives. I think Vivy also has a message about never giving up searching for what you want in life.


The answer to that might change many times, and it may never be such a clear-cut answer that you can find easily. It’s more about continuing to ask yourself and look for your own answer.


M: I see, so it’s about not giving up and continuing to search for your own reason.


U: I like that philosophy, so I tend to write characters who feel that way.


M: “Never stop”. That’s a very nice answer.


U: Are you sure? I think our answers were kinda lame (laughs).



M: When you began writing the scenario for Vivy, did you set out to create a “music-themed Sci-Fi story,” or a “Sci-fi-themed musical?”


N: [George] Wada-san, who’s the producer and the owner of WIT Studio, had the idea for the story. Rather than leaning towards one or the other, we had planned on both from the start. Neither I nor Umehara-san were really thinking anything too music-heavy. Not like singing while fighting, and stuff.


We were thinking of adding a musical scene, not like a big concert or anything, but some kind of singing scene near the story’s ending. We had planned on keeping the music and story separate, more or less, so in that sense, it started out as a music-themed, sci-fi story.



M: So basically, sci-fi with strong musical influence?


N: Yeah, like sci-fi that relies heavily on music. Given the concept we were presented with, I feel like Vivy was our best possible product.


M: When I read the synopsis of Vivy, I was expecting a story about a songstress. But I was very surprised and intrigued when I first saw the key visuals!


N: If you were surprised, then that means Aniplex’s promotional strategy worked!


U: Yeah, the advertising department’s work paid off! (laughs)


N: A strategic victory. From the start, they really piqued your curiosity. 



M: Did you originally plan to finish Vivy in 13 episodes?


N: Actually, we were only going to make 12 episodes. That was the original plan, but when we tried to organize the story into episode 1, episode 2, etc., we just couldn’t manage to fit everything allotted for episode 1 into a single episode.


We had already decided how the story would end, but as we were writing it, we realized that there was just no way we could cram all the stuff we planned for episode 1 into a single episode. So, we begged the producer to let us add another episode.



M: Oh, so that’s why! I’m glad it turned out that way though. The overseas fans were very happy to have more.


N: It would have been near impossible to fit everything into 12 episodes.


U: Yeah, just thinking about it gives me a headache. We were going to include Vivy meeting Matsumoto and the building collapsing, but it dawned on us that it just wasn’t going to happen (laughs).


N: Yeah, impossible in all kinds of ways. But as for the overall series, we planned for it to last one cour. We set out to write a complete story to end with this songstress AI named Vivy would sing, and we detailed what would happen in which episode. 



M: So, from the start, you planned on making it one cour?


N: That’s right.


M: A second cour isn’t likely, then?


N: Both Umehara-san and I felt that everything wrapped up quite nicely, so it just wouldn’t feel right to force the story to continue any further.


M: Ah, so it wasn’t a type of situation where you thought, “If the first cour does well, we can make a second?”


N: I don’t think we could add another cour to the story, even if the first was a smash hit and got rave reviews. 


M: Oh, I’m a little sad to hear that! (laughs)


N: Well, if there’s enough demand, we might be able to put out a voice drama CD or an OVA!


M: I hope you change your minds and decide to do another cour someday! I’m sure fans all over the world would love it.


N: Who knows? Maybe there’d be some way to do a side story that’s unrelated to the main plot like they do with movies for the JUMP series. Like Vivy’s secret sisters, or sealed singularity points. 



M: In episode 12, Vivy travels back to the point before the final battle in order to stop the war between humanity and AI. Is there a reason why she didn’t go back further in time?


N: What we agreed on was that, in episode 1, only information about the future and Matsumoto’s data were sent back 100 years. In episode 12, there was also the need to send back all of Vivy’s data, and when she’s sent back, the Archive satellite [that governs the AI] had fallen, so she didn’t have the means to travel back any further.



N: Another thing is that if Vivy had gone back 100 years yet again with the experience she had, the Archive could have also gone back the same amount of time with its own experience.


That could have resulted in a whole different series of events, and possibly a scenario in which Vivy’s experience would no longer be useful in fighting the Archive, and she may have been less likely to succeed.


In the series, the final confrontation took place with both of them on relatively equal footing, but if they had gone back further, the Archive would have been at an advantage and likely would have won.


M: Umehara-san, do you have anything to add?


U: I think Nagatsuki-san explained it well. There is a brief line by Dr. Matsumoto in Episode 12, where he says that [100 years] is the limit. 




U: The question you brought up was also discussed during the scriptwriting meetings. I remember the point being raised about having her go back further, but then we had to reconcile that with the issue of energy capacity.


N: For the ending, we had even toyed with the idea of Vivy rescuing all of the sisters! (laughs)


U: Yeah, that was kind of a joke scenario that the producer suggested. When we were figuring out what kind of ending to write, he said “What about a super cliche ending like, Vivy teams up with all the sisters and beats up the bad guys?”


M: Is the anti-AI organization, “Toak”, based on any real-life people or groups? Or do you think a group like that will emerge someday?


N: First off, I just want to say we didn’t reference any real-life terrorists! (laughs) Well, it was Umehara-san who came up with the idea, so maybe he referenced some that actually exist.



U: I didn’t reference anything about real-life people, but the name of the group is based on the Tree of All Knowledge from the Garden of Eden story in the Old Testament. Adam and Eve eat the fruit from the tree and become aware and ashamed of their nudity.


I took the first letters from “Tree of All Knowledge” and came up with the name TOAK. They’re an anti-AI organization of humans, who according to the story, were the first to receive “wisdom.” So, in the world of Vivy, that’s how the founders came up with the name as well.


N: As for whether a group like that may emerge someday, I think it’s possible. Just like in the world of Vivy, AI are super-convenient and are becoming integrated into all kinds of things. As that trend continues, I’m fairly certain that there will be similar groups who will form out of anger and resistance towards AI taking work from humans.


M: When the story ends, how much does Vivy remember of her time as “Diva?” Would it be possible for her to regain any lost memories?


N: This is open to interpretation. We made it a point to leave it undecided. Viewers might have been a bit confused when they saw the ending, in which the short-haired Vivy, who looks like a charming, ordinary woman, is talking to Matsumoto.


They might have been full of questions like: “Was everything a dream? Or was it real? How much time has passed? Does Vivy remember everything? Is Matsumoto OK?” and so on. But I think it’s better not to give away the answers. 




N: I think it’s nice that everyone who watched Vivy is able to come up with their own ideal ending. I have my own version of that, and so does Umehara-san. Even between the two of us, we differ on what the “correct” answer is, so we decided to leave it unanswered and let everyone be correct about what happens in the end.


U: I agree with Nagatsuki-san. All of us, including the producer, agree that we’d like the viewers to interpret the ending in their own way. We all have our own opinions and interpretations of what happened. I’d simply like everyone to decide for themselves.


M: I loved the ending. One thing that really got me thinking was why Matsumoto called her “Vivy” and not “Diva…” 



U: That’s exactly the kind of thing we want people to speculate about!


N: I think that’s because to Matsumoto, his partner is Vivy. On the other hand, Navi insists on calling her Diva, even if she knows it’s not true. It’s a very “AI-like” way of seeing it, which I really like.


U: Yeah, she did say that!


M: Yeah, people have been arguing on websites all over the web, especially about the question I just asked. Everyone was confused about the possibility of parallel timelines with different Vivys and Matsumoto. They were desperate to know more about what happened! (laughs)



U: I’m grateful for everyone’s interest. People discuss and debate that sort of thing on the Japanese internet as well, but not as much as they used to. It seems like there’s much more activity on overseas websites, which I’m very happy about. I appreciate people taking their time to think about the work we produced. 



M: My mother tongue is Spanish, and I’ve noticed lots of people in the Latin America region have been raving about how good Vivy is. Do you ever read comments from overseas fans? For example, on Twitter and so on.


N: I read Twitter sometimes, and also those [Japanese] sites that post translated comments from overseas fans.


U: I read them as well. I’m not particularly skilled at other languages, but there are plenty of easy-to-read English comments out there, which I read. It’s very encouraging.


M: Vivy’s story and ending were very well written and nicely concluded, but the setting is so interesting that a lot of people want to see more of it. You mentioned earlier that a second season wouldn’t be likely, but could there be plans for a side story or spinoff at some point?


N: We haven’t decided one way or another yet. It definitely would be tough to justify a second season, but a side story or spinoff is a different matter and not completely out of the question. As for Vivy and Matsumoto, their story is definitely finished.


But if we consider other characters, we could do stuff like what the sisters were doing before the such-and-such day, or what happened while Matsumoto was sleeping between the singularity points.



M: So, Vivy and Matsumoto’s story is finished, but maybe there could be a spinoff or something happening in the same universe.


N: It’s not entirely out of the question. Just yesterday, we were discussing a scenario in which Vivy failed her mission.


U: Yeah, we were! (laughs)


M: I’m sure fans around the world would be delighted if you wrote more content!


N: It’s hard to say no to all those fans. (laughs)



M: Have either of you been particularly interested in any manga or anime lately?


N: If you’ve seen my previous interviews, you’d know I always answer: “Re:Zero” (laughs). But as for more recent anime, I’d say Uma Musume Pretty Derby. You should definitely check that out.


U: I actually haven’t seen it yet.


N: It’s a really exciting sports story all about passion and determination. The ending always makes me choke up. As for manga, I guess I’ve been reading comedy series lately. 


U: Oh, really?


N: Snack Basue is excellent. But I think my current favorite would be This Communication. The main character has a very warped personality and it’s really interesting. It’s being published in Jump Square magazine.


U: Interesting. I’ll have to check it out.


N: Anyway, it’s really good. The creator’s imagination is seriously impressive.


M: Thanks, I’ll have to check it out. How about you, Umehara-san? 


U: I don’t watch too much anime lately, but as for Jump Square manga, I’ve been enjoying Kaiju No. 8. It’s in Jump Square, right?


N: No, I think it’s in Jump Plus.


U: Every manga is interesting in its own way of course, but Kaiju No. 8 is fantastic. Also, Frieren: Beyond Journey’s End, which runs in Weekly Shonen Sunday, is really popular. 


They’re both very interesting series, so I highly recommend them. I believe they’re both being published in other languages as well.



M: Before we finish, do you have any words for your overseas fans?


N: Honestly, Vivy was so much fun to work on. We got to do the kind of story we’re best at and were able to write it how we wanted, so we’re extremely grateful that everyone enjoyed it.


U: I mentioned earlier that we occasionally read comments on the internet from overseas fans, but today’s interview was a powerful reminder that people all over the world are enjoying our work, which makes me really happy. I see how active the fans are, and how passionately they’re discussing and speculating about the story.


I’m sure Nagatsuki-san would agree when I say that support from overseas fans is a huge source of motivation for creators here in Japan. Knowing that you’re all watching our work and cheering us on will encourage us to keep doing our best. Please continue to support us!


M: Thank you for the interview. This was a lot of fun!


N: Thank you as well!



End of interview.



If you’re a fan of sci-fi and time travel anime, Vivy is a must-watch! 


Thank you again to Nagatsuki-sensei, Umehara-sensei, Kimura-san from Aniplex of America, Shiraishi-san and Miyaji-san from WIT Studio, and everyone else that made this interview possible!


Interviewer: Alfred Toh.


Editor: Chelsea McWillis.


DISCLAIMER: All the images above were used with the permission of Aniplex of America. Thank you for always producing top-tier anime!