To be honest, then I had watched the anime before reading the manga. To me, the anime was horrible - since the ending was completely unnecessary, and I felt no remorse for the male lead. Because, he had practically slept with every single girl in the series o__o Also, he only began to feel true remorse for his actions when no one talked to him anymore.
Next to the anime, then the manga is A LOT better. Within the manga, he actually tries to avoid Sekai's affections, and concentrates on Kotonoha. He admits that "he's disgusting" for even thinking these kinds of thoughts. When Sekai kisses him, he pushes her off and tells her he won't forgive this next time. And, he confronts Sekai and chose Kotonoha, begging for her forgiveness.
Both endings were completley.. unnecessary and out of nowhere, and was like it was randomly slabbed on for some ... "drama/suspense?" It completely ruined the plotline. The anime is a lot more gruesome with the gore, and graphic. The manga however, deviates from this and minimal violence is shown. The ending is ambiguous though, and I was a little confused.
I just find it funny how the girls totally blame the other and not the guy.
**Overall, in comparison to the anime then it deserves a 7/7.5? As a stand alone... 5-6? **