@Frizzlewits That last punnett square is her and Kazuki's, she asked him his blood group to find what their kid's blood group could be in the future. Quite adorable indeed.
It isn't that weird for these kids to fall in love with their teachers. In fact I also liked one of my teachers when I was in middle school, she was also very nice to me. Having those feelings is natural but of course you are later hit with the fact that the relationship you want is not...
Why is everyone expect the main so dang obsessive and creepy ? I was more or less fine with the teacher until last chapter, that ending was just too weird, although I understand that Nagai also has feelings for her. Then we meet this creepy peeping tom of a senior chanting her name again and...