Since the first few episodes of Boku no Hero Academia (My Hero Academia), viewers have witnessed the tumultuous relationship between the shy and optimistic Izuku Midoriya and his abrasive and brash frenemy, Katsuki Bakugo (Kacchan). 

As part of this bad relationship, Kacchan mockingly dubs Midoriya “Deku”. But why? This is where many posts on the Internet get confused. 

Watch the video below, where we explain to you the meaning of Deku.

Or you can keep reading the article. But, I highly recommend you to watch the video, though.

Midoriya Izuki name’s meaning

In Japanese, the name of Midoriya Izuku is written 緑谷 .

  • 緑 (midori) 谷 (ya) 
  • 出 (izu) 久 (ku) 

But, the kanji (Japanese characters) have more than one reading so 出(izu), and 久(ku), the kanji that make up the name of Midoriya can have multiple pronunciations.

Note: Izuku is his name and Midoriya is his last name.

Bakugo & Deku

In one episode, when Bakugo is reading Midoriya’s name, he tells him that his last name can also be read as “Deku”.

And yes, “de” is another reading of the kanji 出.

So, according to Katsuki (Bakugo), instead of

出 (izu) 久 (ku)

The pronunciation of Midoriya’s name is:

出 (de) 久 (ku)

Thus, is Deku a derogatory term?

No, but Kacchan uses it as an abbreviation of the word Dekunobou whose meaning is “good for nothing” or in the exact words of Kacchan “someone who can’t do anything.”

Midoriya & Ochaco

Being an insulting word, why does Deku choose it as his superhero name?

Midoriya mentions:

“I didn’t like this name until now, but someone changed the meaning of it, and that had a huge impact of it. It made me really happy.” – Midoriya

He was of course referring to Ochako Uraraka (a.k.a Uravity). In an episode, she said to Midoriya,

“But Deku gives off a feeling of “I can do it.” I like the nickname.”

Wait, but doesn’t “Deku” refer to someone who can’t do anything?

Yes, but it can also be the abbreviation of the word dekiru which is the Japanese verb that you use express ability to be able to do something (i.e. can, or be able to).

For example :

Watashi wa nihongo ga dekiru
I can speak Japanese.

Using this, Uraraka relates the word deku with the ability to do something.

In other words, Deku means that Midoriya is able to do anything.

Although in Japanese the term “DEKU” in it itself has NO meaning (so don’t try and use it because nobody will understand you) in Boku No Hero Academia the phrase is an abbreviation of the words Dekunobou and Dekiru.

To sum it up

For Kacchan:

Dekunobou -> Deku: the one who can’t achieve/do anything.

For Uraraka:

Dekiru -> Deku: the one who can achieve/do anything.

I confirmed all of the above with my Japanese friends.

Bonus: Deku T-Shirts

Some people asked what is the meaning of the T-shirts that Deku is wearing, here is a translation:

  • ネルシャツ: Flannel Shirt
  • ドレスシャッツ: Dress Shirt
  • Tシャツ: T-Shirt
  • シーツ: Bed Shirt
Also, season 6 has been scheduled to air on October 1, 2022

Boku no Hero Academia (Season 6)
© 堀越耕平/集英社・僕のヒーローアカデミア製作委員会