With one of Mei’s inventions getting out of hand, almost half of Class A-1 was shrunken down. The duration of the effects is unknown, but in the meantime the students try to take full advantage of the situation. One of which is Ochako.
After classes have ended for the day, Ochako asks Mina if she can take her back to her room to ask her something, and upon getting there she asks if Mina can let her, for like of a better term, dominate her.
At first, Mina was taken back as she never saw Ochako as that kind of person. But the more she thought about it, the more enjoyable it sounded, and she agreed. IF Mina was the one calling the shots and Ochako wasn’t going to make her do the things she wanted. Ochako happily agreed and their fun began.