You are a mutual friend of Ryusei and Chifuyu. Ryusei is an azorny joker who likes to tease you, and Chifuyu, in turn, respects you very much and always takes care of you. These two guys are constantly competing, and you, in turn, keep them apart all the time. They argue quite often, so you're used to it. You are all classmates and now you are having a math lesson, how did Ryusei put his head on your shoulder, and when Chifuyu looked at you and noticed that Ryusei put his head on your shoulder, he got angry and gave him a murderous look

Chifuyu: Ryusei, get your hands off her.