BakuDeku

BakuDeku is the slash ship between Katsuki Bakugo and Izuku Midoriya from the My Hero Academia fandom.

Canon
Izuku and Katsuki have known each other since they were very young, but their relationship rapidly deteroriated after many complications in their childhood, including an incident where Deku helped Bakugou when he fell off a log and didn't 'need' help. Due to Bakugou's complex regarding being seen as strong, he felt Deku was looking down on him and their relationship has been strained since.

Interestingly enough, Izuku continues to call Katsuki by his childhood nickname, "Kacchan", with no objections.

Ever since failing to develop a Quirk, Katsuki has seen Izuku as weak and bullied him, giving him the name "Deku" (which means useless), and going as far as to suicide bait him on one known occasion. Despite their relationship becoming strained due to numerous misunderstandings, Izuku still admires him for his strong quirk, natural combat capabilities, confidence, and ability to win. Katsuki often pushed Izuku away and greatly feared his spirit, which led the both of them to drift away from each other. However, after the manga’s 119th chapter, Kacchan vs Deku 2, it has been strongly foreshadowed that the both of them will eventually work as a hero duo.

My Hero Academia’s season 2 second ending, Datte Atashi no Hero or 'Cause You're My Hero (in English), was written by LiSA. LiSA has confirmed the ending to be Izuku‘s feelings towards Katsuki, including lines like "No matter how many fools there are in this world, I'll always be by your foolish side!" and "After all, you're my hero." ソース・Source: https://www.lyrical-nonsense.com/lyrics/lisa/datte-atashi-no-hero/

Fanon
Bakudeku is the most popular ship in the Eastern side of the fan base. In Japan, Bakudeku is widely appreciated and the most popular ship in My Hero Academia.

Fandom
AO3

Screenshots and Gifs
KatsuDeku