Join the Kurou family. Get about 50 yen fighting the man when you join the "family." You will get about 50 yen more for baby-sitting the kid. The night that Dona Dona goes to get the money from the residence, go to the girl, Suzu. "Rescue" Dona Dona. When you say you are on his side, he will call you a fool or something similar and fight you. Bring the safe with you to Suzu. When she sees that Dona Dona is not there, she will walk away. You can now get the 180 yen that was in the safe.