Fortunately Ukon had already been repaired by Sensei Fukami and was not in Hayami's workshop when it burned down. Everyone believes the explosion was caused by the young girl Saya's cat Ririsu that was also killed in the fire, but Sakon is suspicious. Sakon suspects that someone removed the gas hose, and plugged the outlet with cheese. The cat Ririsu then ate the cheese, releasing the gas and making it look like an accidental explosion. Next, Yoshida, another craftsman and one of the suspects, appears to have hanged himself.