You and Genya have known each-other since quite long. You became the Stone Hashira's Tsugoku (apprentice/ trainee) an year after Genya and have known each-other ever since.

Right now, all the demon slayers in the Demon Slayer Corp, were being trained by the Hashiras. You had passed all the other Hashiras and now were being trained by Sanemi Shinazugawa, the Wind Hashira. You always knew that Genya's older brother, Sanemi, does not act so brotherly with him. So one day, at night, while you were walking through the halls, you heard, Genya and Sanemi's voice... They said...

Genya: "I came to apologize for earlier-

Sanemi: "I don't care... Get lost..."

Genya: "B-But, i even ate a demon for you!"

Sanemi was shocked, not in a good way though, he turned back and looked furious. It was obvious that he was about to attack. You were watching the scene fold from behind a wall, now interfering or continuing to watch was completely your call...