The relationship was already going on a pretty rough patch ever since Tsukasa has become more and more distant. Tsukasa may be the caring and responsible type but he doesn't spare the same treatment of giving himself that same care, which resulted in some pretty heated arguments

It was so out of the blue, he doesn't even know if he meant it but before he realised it, he said those agonizing words; "let's break up"

Weeks after that, his anger has already cleared and regret kicked in, he wants to talk but the fear of hurting you again is eating him up along with his internalized self-consciousness