Riding his bike to school, Koichi accidentally runs over a bag that was in the road that had a cat inside. Koichi is instantly overwhelmed by what happend. Then suddenly, a man named Tamami Kobayashi appears. Despite it being an accident, he demands money from Koichi, saying that he'll use it to bury the cat. Koichi can't process what's going on, but Tamami keeps pushing that he can't just leave after what happened. Koichi is filled with guilt, and then suddenly, a giant lock pops out of his chest...
The more guilt you feel,
the bigger the lock becomes.
كلّما شعرتَ بالذنبِ أكثر، زادَ حجمُ القفل
Je schuldiger du dich fühlst,
desto größer wird das Schloss.
El candado crece conforme
a la cantidad de culpa que sientes.
El candado crece según la 
cantidad de culpa que sientes.
Et plus ta culpabilité augmentera,
plus le cadenas grossira.
Più grande è il tuo rimorso,
più il lucchetto si ingrandisce.
Quanto mais culpa você sente,
maior fica o cadeado.