In search of a fresh start, househusband Masaki Fujiyoshi, his wife Hiromu, and their young son Hikari move to a new neighborhood. Their relationship has been strained due to societal prejudice, as Masaki is an omega, a secondary gender with the ability to bear children. Despite Hiromu being an alpha, another secondary gender deemed superior, they still face significant discrimination that jeopardizes their aspirations for a serene family life.
Fortunately, they find companionship. Hikari befriends Yuuki Hirai, a solitary college student living next door. Although initially wary, Yuuki develops a strong connection with the boy. Additionally, the family receives support from Tomohiro "Matsu" Matsuo, Hiromu's old friend and coworker.
Despite the seemingly perfect life the young family has established, a return of someone from their past threatens to upset this newfound peace.