I'm known as "Dekunobou." I'm big and slow, so the nickname stuck since childhood. I've grown older, my younger brother is married with a family, and now I'm unemployed... It's so pathetic it brings tears to my eyes. One day, my brother and his wife go on a trip and ask me to watch their house. But there's one problem—my brother's daughter, a bratty, arrogant niece who immediately mocks me as "weakling, weakling" the moment I arrive, trying to assert dominance. For the next three days, it's just me and this damn kid living alone together. Can I survive this situation?