Soon after becoming a lawyer, Hikawa quickly adapts to his new life and begins a new relationship. One day, he learns that his ex with whom he was in a relationship three years ago, Masumi Akagi, has been harassed by another new teacher and is even forced to quit his job. Even though the two have not maintained contact, Hikawa still decides to help out and seek justice for Akagi, but this decision leads to his stable life beginning to change…

Toru Hikawa is a new math teacher at Sakuradai High School, who will lead his class with his teaching assistant Masumi Akagi. The handsome and friendly Hikawa quickly wins over teachers and students alike, and Akagi was head over heels with him from the very beginning. One day, Akagi sees a sleeping Hikawa's cute face and can't resist kissing him! He was shocked to be caught by a student, so what will he do next? And will Hikawa, who has spoken about his plans to marry his girlfriend, finally be moved by Akagi?

Season 0 of House of the Dragon premiered on December 28, 2020.