Eh, it's pretty bad.
I didn't hate it. I think it's decent to worse-than-good but it's not horrible.
First, the characters and their dynamic.
There are three main characters:
Natsuo is your typical romance anime protagonist, nothing more to say really.
Rui, your typical romance anime tsundere but she has a little more depth to her character than Natsuo, so it's fine in my book. Plus, her design in itself stands out a lot more than N, which kind of makes her the true protagonist in my eyes, if that makes sense. I think it's more interesting if you look at it that way.
Finally, we have Hina. Ahhhhhh, what a horrible person. Really, I have no idea how you are supposed to like this character. This b*tch is literally manipulating a high-school student (6 year gap btw, this is totally fine) to almost completely remove himself from society and lie to EVERYONE HE KNOWS (!!!) about the nature of their relationship.
Man, that's so fucked up.
Little side note on N x H, even ignoring the fact that it's morally wrong and kinda fucked up, it just feels so wrong! Not morally, but it's just awkward. I can't really describe it but every time they were on screen together I felt some sort of uneasiness because I feared it was gonna go to shit.
To summarize, the characters are mostly one dimensional don't really make much sense except for Rui, who I find to be a very well crafted, believable and most important of all relatable character.
My second major issue is that the story is very awkwardly written.
Depending on how much you read into things, it's obvious by episode 1 perhaps 2 that Natsuo and Rui are supposed to end together.
But by episode 10 and 11 (only ~9% of the anime to go btw), he's still madly in love with Hina willing to go as far as to die with her (???), which I find just wrong and doesn't work at all.
How is the MC supposed to let go of her and learn to accept that Rui is in love with him and he might be too in such a short period of time??
Well, short answer, he doesn't.
He fucking writes a book and now everything is better.
Even after externalizing it, he still loves her. Okay so what was the point ?
No idea.
And then Rui decides to force herself on him.
Whatever, who gives a fuck. It doesn't make any sense and I feel robbed.
I understand that it would have been just another generic "in the end I realized I really loved you but couldn't admit it" or some shit type anime end but really, that would have been so much better.
You leave the watcher with a feeling of emptiness after watching 12 episodes, which is quite a feat. Really, what harm would have been done in adding one or two episodes to properly wrap up things together? That would have been so much better.
Eh, who cares.
I don't regret watching it but damn, what a bad taste it leaves in your mouth.
4/10