A story about brothers. Due to renovations to the house, the second son, Yasuhiro Takashima, and his mother, Aoi Takashima, are living at the house of his aunt, Misako Kuroyanagi, who is his older sister. She is renting a room from her cousin, Tatsuo Kuroyanagi, who goes to university in Tokyo and lives alone. My mother, too, seems to be conscious of the fact that she is living in a rented house, but she does her best to do the housework without taking any breaks. While watching his mother like that, Yasuhiro finally realized... And Yohei Takashima, the eldest son of an elite office worker who spends his busy days, has also noticed... My mother has an incredibly beautiful butt! !