Ema Hinata, a kind-hearted girl raised solely by her father, receives unexpected news of his impending marriage to Miwa Asahina, a wealthy designer. Excited for a new home, Ema soon discovers that her family will expand exponentially as she gains not one or two, but 13 step-brothers. Seeking to give her father space, Ema moves into Sunrise Residence, her new abode shared with her newfound siblings. However, amidst this unconventional family dynamic, Ema realizes that the affection she craves may come with unexpected complexities. Each step-brother harbors feelings for Ema that transcend mere sibling bonds, presenting a challenge for her quest for familial love. Faced with the dilemma of reciprocating these unique affections or pursuing a different path, Ema must navigate a web of emotions to uncover where her heart truly lies.