Sisters - The Light of You(2021)

Nozomi, who has a younger sister with a mental disability, has not revealed her sister's existence to her lover Takashi - who is confused when he discovers her existence. From there, he faces the concerns peculiar to families with disabilities, one after the other, and despairs in his own life, which is far from "normal" life, while Nozomi tries to give up his marriage to Takashi.