This manga was so refreshing! I enjoyed every part of it, it was just so cute and adorable! It made me smile, laugh, go ''awww, cute!'' and even giggle in a fangirling way like I never did before. That is why I give it a perfect score; it's because I enjoyed it so much!
If you look it up in a more objective way, however, it does have some flaws, but would still deserve a 8 or 9 score. Let me add some details here.
Story: The story felt a bit cliché, but was handled so well that it's forgiveable. It is along the lines of
''I love this person so much that I'm ready to open up my heart one more time but I'm also scared of getting hurt'' and ''A big misunderstanding causes drama''. Yes, it is not an outstanding or super original story, but it is told well and gives more space for more important stuff like the characters.
Characters: Both characters have a well defined personnality. Some might find a bit of dejà-vu in them, but I felt like they were really unique; Keito in particular. He his a scary looking guy at first, but when you get to know him he is the cutest awkward man ever! Serizawa seemed like a really chearful and happy man at first, but we get to learn more about who he really his and tries to be. Even if the manga has only one volume, we can feel the characters grow quite a lot, which is really nice.
Art: I loved the art! The drawings are really pretty, with nice straight lines and just enough details. The chibi and cute faces were just so adorable too!
Enjoyment: Well, this pretty much brings you to my frist paragraph. I enjoyed every single part of this manga so much and after each chapter I was a bit sad because I knew there was so little left to read!
Overall: This is a great manga and I think any shonen-ai fan could enjoy it. The story is just so simple, cute and pure. It really makes you feel all happy and giggly!