Tokyo, love before they become female ghosts

Takuya Hasegawa was transported to an island nation plagued by supernatural phenomena. To become stronger, and more importantly, to survive, he was forced to forge connections with infamous, dangerous women, protecting their humanity and ensuring they wouldn't transform into demons or monsters to destroy the world! Because if one of them died, she would become a terrifying female ghost with an incredible sonic boom, a katana-like warrior who would climb down the stairs! If one died, many more would appear, until they filled the entire world, even the universe! As for the other… if she died, Takuya felt that all of humanity's video-related technology could be scrapped and restarted… Takuya diligently, cautiously, and fearfully maintained the humanity of these women, watching their humanity points slowly increase, his heart filled with glory and pride. It was I who protected this world! But one day, as the women barged into his bedroom, eager to prove themselves, and as their humanity points became completely invisible, Takuya suddenly realized… You bastard system, you schemed against me! Why didn't you tell me that the Human Reason Value was also a form of favorability?!