Age gap love story between a teacher and an ex-student. Takamine has been in love with his highschool teacher Natsume and has been caring for him because of his clumsy nature. He becomes a teacher himself so he could meet Natsume again and be with him. After drinking out with other colleagues, Natsume gets drunk and Takamine offers to bring him home. However, an ulterior motive is hiding behind this act of kindness. Takamine takes advantage of Natsume while drunk and sleeping but Natsume seems to be aware of it and lets Takamine have sex with him. Takamine eventually confesses and they start kinda doing stuff but Natsume couldn't commit initially because he wants Takamine to have a better future (this way of thinking is partly because Takamine was his ex-student). Eventually they get together and it gets revealed that Natsume actually only acts clumsy in front of Takamine so it's kinda showing that Natsume has liked Takamine since his highschool days.
Sensei, Anata ni Chikadukitai