This manga is very sweet. It's kind of a stereotypical romance between teacher and student, but I feel like it was done well. The main story (chapters 1-5, and 7.5 at the end) is well-developed, and the climax in chapter 5 is very enjoyable. The conclusion leaves a little bit to be desired (a.k.a., seeing their relationship now that they're together), but the existence of chapter 7.5 helps a little bit.
In this manga, the reason the sensei rejects the relationship initially is not because the other person is his student (and a man, it is clear the sensei is gay), but it has to
do with the sensei's complex past. I like how this is used instead of the "but we're both guys!" or the "you're my student" trope that seem to pervade the BL genre.
A note about the one-shots (chapters 6 and 7): they are slightly stereotypical, but still enjoyable nonetheless. My only issue with them is that the main characters in both look REALLY SIMILAR to the ones in chapters 1-5. When I first read chapters 6 and 7, I thought the main characters were already cheating on each other! Thankfully, the names are different, but if you're bad with names like me, then beware of that.
This is my first review, so I hope it was helpful.