Piefan, are you talking about Yumika (Chance's mother) or Yuzumi (Kitti's classmate who proposed to the head of the school)? They are both pretty disturbing characters, but there is a big difference, since Yuzumi is a very friendly girl even though she's kind of creepy and stubborn, whereas Yumika is just… not meant to be anyone's mother… or anyone's wife for that matter, so if you were talking about her, I understand why you don't see why Chance's dad ever married her. That's probably what you meant, but since we were also talking about Yuzumi's marriage proposal, I wanted to check in case you were mixed up.
Regarding Mana, I think that if she's not real, it's still understandable that Chance has an imaginary friend, since he made her up before he had any real friends, and also, if you have Yumika for a mother, you're going to need someone - real or not real - to comfort you O.O
Edit: There is actually a headcanon that says the reason Chance named his imaginary friend "Mana" is because it sounds like "Mama"…I'm trying to imagine now what Chance's reaction would be to Washa x Mana: I think at first he would be totally shocked ("I thought you hated her!") and then once he was used to the idea he would get really excited, and then at some point he would get protective and be like "Mana is way too young to have a boyfriend!" and then Washa would answer: "Well, when did you first meet her? When you were four? Then she's at least thirteen…" And Chance would be all in denial: "Mana is not thirteen!!!", and then Washa would reply: "Why not? Because she's short? Is that why?" LOL this is genius XD
Edit 2: Aliria, could you change Naoki's picture on the Wiki to
this one instead of Naoki's sign? I don't know how to do that myself…
Also,
@Everyone: I renewed the poll since I finished drawing Naoki, so you guys can vote again ^^.