The story is interesting and well written with some plot twists along the way. The "die and go back in time" mechanic is not new at this point since we have shows like Re:Zero and other mangas as well, like Tales of Demons and Gods, for example. Even if that's the case, that mechanic is well implemented in this story, giving the readers a justification in the final chapters for why that happened. The main character's development is solid and some of his decisions are justified due to the nature of the episodes of the manga. He doesn't let despair get him and always comes up with a new plan to test and see if it works.
Although the ending could've been better and the story could have progressed a little more I think it's better to leave it as it is than risk ruining it.
With that said, it still is a good manga that I definitely recommend.
