Leilu

Side-story episode!

Action happening at slaughter room then on ruined animal dorminatory and Lugus room on terrible mouse/cute critters hospital
After Leilu killed Lake and one mouse, she managed to free her sister Leima from being tortured by some mice at the slaughter room, and now they are starving
Leima had an idea and told her that the slime boy (whom Leima had met and protected before, though Leilu doesn't know that) could help them, so they free him. He joins them to find food, and they manage to escape using a ventilation duct and scrambling out of a window (where other animals usually get food). Now they are in the ruined animal dormitory (where something strange seems to have happened). They go into a room and talk about how much they hate Lugus (the yellow bunny of this place who is really strange)
Leima is still haunted by memories of the past, and Leilu tries to help her. Both rabbits are now looking at photos when they see something (a photo that perhaps only the two of them recognize)
So you are an anthropomorphic animal (you can choose what you are) (and you can choose whether to help them or not). You are now walking through the ruined animal dormitory when you encounter these three in Lugus's room