All around Mana, humans are being stricken with a strange illness that turns them all wrinkly and causes them to fall unconscious. She notices that her classmate Tsutomu is acting oddly, but he keeps telling her to leave him alone. Worried, Mana goes to his apartment building. But, faced with his mother`s piercing gaze, Mana runs away. That night, Mana tells Kitaro about Tsutomu and his mother`s odd behavior. Wondering if it`s somehow connected to the strange illness, Kitaro and Cat-girl go to Tsutomu`s apartment. What they see there, the truth behind the illness is...?!