I found a bug where Natsuki just isn't in the character list. I'm pretty far into the game, I've met all of the main characters, and I've even done a few of Natsuki's events but she still appears as a locked character and I can't see any of her hints.
By the way, I really love this game. All of the characters are written very well and the story is quite interesting. Also Arvin looks kind of similar to me, has a similar sounding name to me IRL, and has a similar personality to me, so seeing him have such a nice relationship with Saori when I've been single my entire life genuinely brought me close to tears.
