Random headcanons, don't mind me.

1. Todoroki listens to hard rock and hesvy metal a lot. Contrary to popular belief, his favorite song is not Hot and Cold by Katy Perry. His favorite song is Numb by Linkin Park, because of how much he relates to the lyrics.
-He actually has developed a strong dislike for Hot and Cold because after Mina brought it up in a conversation, his classmates wouldn't stop teasing him about it.
-After Jiro found out abiut his taste in music, they occasionally geek out about hard rock and heavy metal bands they both like. Jiro's happy to find another metalhead besides her family.

2. The girls locker room is usually full of sexual teasing, most of which is from Mina and Toru to either Jiro, Momo, or Uraraka, mostly Jiro because she's actually super shy about that kind of stuff.
-Tsu doesn't actually care when they tease her. She finds it funny how flustered the others get though.

3. Jiro doesn't just like rock and metal. She listens to a mixture of everything, from classical orchestrations, video game soundtracks, and Halsey, to Imagine Dragons, Linkin Park, and Three Days Grace.

4. Tsuyu has green blood because of her quirk. This was discovered during a training excersize when Momo hit her too hard with her steel pole. Needless to say, people were shocked at that fact.

5. Tamaki has had a huge crush on Mirio since they were little.

6. The boys locker room usually consists of Bakugo either A. Making fun of Deku's tiny dick, B. Yelling at Kirishima and Kaminari for teasing him about how gay he is, or C. Yelling at Todoroki for his smartass responses to literally every other thing he says.
E.g:
Bakugo: Deku has a tiny dick
Deku: Kacchan! ;-;
Todoroki, in a completely monotone voice: It's not much smaller then your own Bakugo.
*Cue entire locker room going OOH-*
Bakugo: ÒnÓ