Thirty-year-old, unemployed Kenji (Kaku Tomohiro) spends his days listlessly at his parent's home, which is set to be torn down any day now. He relives his childhood when a third grader out for summer vacation nails Kenji with a water balloon, and Kenji fights back.

September 20th. Sunny. I wonder if it bugs me so much because I can't see it. I've gotten totally obsessed with finding out what's inside that bump. It's all I think about on my way to school, in the bathtub, and when I'm trying to fall asleep at night. I mean, if I could just figure out what's inside that bump, I'm sure I could figure out lots of other things too.