While the ending in the first game appears to be true good, it only appears this way without the future context. This game shows us how, despite the seemingly happy ending presented in the first, the relationship with Koko ultimately doesnt stay so happy. The point of this game is almost to show this, the kind of monster people that Koko and Reiko are means they essentially unable to have a long steady continuous relationship (its been a long time since i played so forgive me if i get this a bit wrong). If this game had a true good ending, it would only be a false promise like the one of the previous game. Maybe the girl in Koko was right to warn us about her.
Maybe i should just leave this 8 month old comment alone, but i wanted to comment on this while i was reminiscing on this game