A-ko started a part-time job at a convenience store to help with the household finances. The part-timer B-man, a 大〇生 who works there, fell in love at first sight with A-ko, who looks younger than her real age — young enough to pass for someone in their early twenties. A-ko, who has been sexless with her husband for a long time, gradually grows attracted to B-man, and after a fight with her husband she has an affair with B-man to vent. B-man, besides his youthful vigor, is obsessed with butts and is an insatiable stud who can ejaculate and get hard again after repeated doggy-style sessions. Whi