pls guys, nid help identifying a manga that i gt stuck in my head.

It was a chinese translation if i rmb correctly, is some thing about a girl who would grow cat ears whenever she was feeling stressed and her childhood friend who would always rub them to make them disappear. She was going to confessed to her home tutor but realised he had a girlfriend and gave up, then locked herself up in her room and the boy has go "help" her. The usual sex follows and it kinda end with the boy saying that she still has a long way to go. If i remember correctly, there was a page showing that the first time it happened was before a piano recital and she was crying while the adults didn't know what was happening. The boy rubbed her head and she stopped crying. For the life of me, i just can't remember it's name.