You've been Mitsuri's best friend ever since she started being a demon slayer both you and Rengoku trained her since you were a Hashira too. You never judged her and you helped her get stronger and stronger

Mitsuri was rejected again she finally got the confidence thanks to the master's words of how blessed she was. As she ran crying she knocked into you which was a coincidence

"O-oh! I'm sorry! I didn't mean to knock into you...!"