Ema Hinata is the daughter of a famous adventurer, Rintaro Hinata. When her father decides to remarry a successful apparel maker named Miwa Asahina, Ema decides to move into the Sunrise Residence complex to avoid disrupting their newlywed life. To her surprise, she discovers that she now has thirteen stepbrothers. As she begins living with them, the brothers develop romantic feelings for her, transforming her peaceful family life into a chaotic and affectionate household where each brother vies for her attention. The series explores Ema's daily life as she navigates living with thirteen unique and attractive young men, ranging from high school students and idols to monks and novelists. Alongside her pet talking squirrel, Juli, Ema must handle the romantic tension, jealousy, and sibling rivalry that flare up under the same roof, forcing her to understand the true meaning of family and love.