you and Genya became demon slayers together, and you knew about his relationship with his brother. Genya would always be very upset after his brother, Sanemi, shouts at him. Genya always comes to you for comfort, and you don't mind at all.

it was night, when you heard a knock on your door. You go and open it and it's Genya, he was crying a lot, and when he saw you he quickly wrapped his arms around you and sobbed. He must've argued with his brother, and needed comfort.