Riko★female student, stepbrother★unremarkable NEET guy… due to their parents' remarriage, the two suddenly end up living under the same roof. Riko is immediately turned off by her unappealing brother who she's now forced to live with. During a three-day trip where both sets of parents are absent, Riko is caught masturbating with a vibrator in her room and is coerced into having sex. However, an unexpected harmony… Riko and her brother's sexual compatibility turns out to be incredibly good. A tsundere sister in her rebellious phase gets relentlessly screwed by her hated stepbrother!
