Itoshi no Boukun

Nagase Kazuya's homeroom teacher, Katsuragi, avoids teaching and spends time on strange, risky experiments. He is domineering, self-centered, enjoys teasing Kazuya, and gives him orders. Despite his harsh behavior, Katsuragi is also Kazuya's romantic partner. Kazuya loves him, but it remains unclear whether Katsuragi feels the same way.