With her father’s remarriage, Ema has unexpectedly gained thirteen new brothers. Today marks the day she will meet them all, a prospect that promises to be a rather eventful one.

Having spent much of her life in solitude with her father, who was frequently away on business, Ema finds a quiet joy in belonging to a large family. Yet, she also experiences unexpected encounters with Futo, the family’s charismatic but of…

Ema discovers the nature of Futo’s desire. As her father’s wedding draws near, she encounters the final of the thirteen brothers.

A couple of months into her new life, Ema finds her connections with her brothers evolving. She cheers on Tsubaki's pursuit of a voice acting career, and simultaneously deepens her friendship with Natsume through shared gaming sessions.

With no provisions for a proper meal at home, Ema finds herself enjoying a picnic beneath the blossoming cherry trees. It is, at last, an opportunity for her to watch Subaru play basketball.

A surprise awaits Ema and Yusuke at school, orchestrated by Futo. The photographs Ema has been taking, a habit no one of the brothers indulges in, are beginning to attract notice.

The school’s Culture Festival loomed for Ema, Yusuke, and Futo, a harbinger of Futo's customary antics. Meanwhile, at home, Azusa appeared increasingly strained by the weight of a role he had secured from Tsubaki.

Azusa’s sudden illness weighs heavily on Tsubaki, who grapples with the unsettling consequences of their earlier conflict. Meanwhile, Ema diligently offers assistance wherever she can find a need.

Ema was distressed, wounded by what she had discovered in the official family register. As she delved deeper into its pages, she began to understand more about Natsume, Louis, and the Asahina family.

The recent turn of events had rendered the Asahina family’s overseas vacation impossible. Consequently, they opted for a shorter journey, a local outing centered around the pleasures of a summer festival.

With the college entrance exams looming, Ema discovers the warmth of her siblings' support. Yet, amidst the academic pressure, a different kind of anticipation hangs in the air: many of them also await news from her regarding a romantic int…

With the looming college entrance exams now concluded, Ema reflects deeply on the significance of her brothers in her life, reaffirming a resolve she’d made to be more forthcoming with them.