In a rural junior high school, a boy and a girl promise everlasting friendship, and as two years pass harmoniously, the tale unfolds... This story delves into the lives of Inuzuka Himari, a girl yet to experience her first love, and Natsume Yuu, a boy with a deep affection for flowers. Both remain inseparable best friends in their second year of high school, bonded by their mutual membership in the gardening club. Occasionally, Hiyori playfully taunts Yuu, joking about marriage and the awkwardness of being called 'brother-in-law' by her brother. However, when Yuu's childhood crush reenters his life, the dynamics of their relationship undergo a sudden shift! Will Himari's newfound emotions help her transcend the confines of being just an 'ideal friend'?