Steve 'Leif' Kareha

I think Madsotsuki was raped and killed by Poniko. Here's the evidence.

Madsotsukis room resembles Poniko's room alot. Poniko might have been Madsotsuki's lover or maybe even just a friend.

When you go to the snow world you have to enter an igloo to find Poniko's house, she might have felt cold and lonly in need of a friend. You then find ballons that telleport you to her house, this has hints of a party or sleep over maybe.

When you enter Pinoko's house you need to switch the light on and off usually more than once, Madsotuki must have invited her over alot and turning the light of might have hinted a sleep over.

Uboa suddenly appears as I believe Pinoko's face in the shadows. Uboa only aproaches you when you are a cat. This might have been a role Madsotsuki was playing when she was raped

The groping hands in the Uboa dimension are bloody, she was probably also killed during this or perhaps it was a gang rape and the other rapist where hiding in the shadows waiting for Madsotsuki. Poniko could have also been the victim.