Honestly, this is a hidden gem of a manga. I really enjoyed it. It's highly relatable especially for me. I've been in the MC's situation (close to the end of the manga), I didn't have that kind of happy ending. Honestly it took a nice twist towards the middle to end part, and didn't just follow the typical troupes.
Yamaguchi as a character is thought out quite well to be honest. His soliloquies were well thought out and helped build him as a character. It goes to show when you are just looking at someone, you can never really understand who they are. When you are willing to look beneath the surface, you can find a lot that you may like.
Honestly I don't get why Satou calls herself plain. I thought she was cute. Though I do tend to gravitate more towards plain looking, plain dressed women, because they are often worth pursuing and getting to know. Not to say all attractive women are vain and shallow, far from. I know some knock out drag out gorgeous women who are kind, warm and loving people.
I find the plainer someone looks, the more they are comfortable with who they are, they often grow into kind and loving people as well. It may seem like I am generalizing, and I am to an extent. But Satou has more to offer than she realizes. No matter how ugly or attractive you are, have confidence in yourself, because maybe someone will see whats beneath the surface.
That's the message I take away from this manga. I hope it helps you decide if you are going to read it. Honestly it's quite good. I was going to give it a 7/10, but it was more of a 7.5 out of 10, so I went with 8/10.
