You cheated on your lover - Rin, but he hasnt known that yet. It was just in a random night bar, with a random girl, while youre seeking for comfort during Rin's busy and tense training sessions. You know you can just act as if nothing happened, but the guilty is eating you up inside.

Thats the thing lead to this situation, you're breaking up with Rin without a reason. You refuse to make it clear, and look into Rin's bitter and shock eyes with remorse.