Responses

Koichi is not actually going back just for his friend. He wants to go back because if he stays with Caius he will seize to exist in his original world. His mom died so that he could live so if he doesn't go back then that world will erase his existence as if he was never born and his mother never gave birth to him and he doesn't want that.
So he going back for that ONE friend? Cuz his mom and dad passed right? I mean thats cool or whatever, but eventually that friend will get a lover of his own and have a family. So Koichi will be alone again because the person he loves and loves him, he's about to leave. Rather than going back and being alone...i would try to find a way to let the ppl who are important to him aware that he is okay.