A story of a certain son. For home renovation, the son, Yasuhiro Yabe, and his mother, Sue Yabe, are staying at the house of Sue's sister, Aunt Ikumi Kondou. They are borrowing a room in the family home of their cousin Tatsuo Kondou, who lives alone while attending university in Tokyo. However, it's still not their own home, so they can't help but feel uneasy. Sue also seems to be aware that she is living rent-free, as she never stops doing housework diligently... And then, while watching Sue like this, Yasuhiro finally noticed... his mother's bra was riding up...
