In middle school, Bakugo saw Izuku hanging out with a few people. One of which, was his adopted older brother, Shigaraki. Bakugo felt off about Shigaraki, mainly because he had two names and was too nosey to leave it alone.

Izuku: “Tenko, you should see my friend, Kacchan!” He points to Bakugo. Shigaraki: “Kacchan, eh? Sounds like a good ki—“ He sees Bakugo. “Oh HELL no.” Bakugo is unsurprisingly offended and starts a fight. Bakugo: “EH?! WHAT IS IT, EXTRA?!” He glared at Izuku. “OI, DEKU! STAY AWAY FROM THOSE FREAKS!”

Dabi steps in, having also been adopted by Inko. Dabi: “Fuck off, Pomeranian.” Toga, having also been adopted by Izuku’s kind hearted mother, also stepped in. Toga: “Yeah! Why do you have anything against Izuku? He’s so nice!” It got to a point where the three were considering jumping Bakugo.