Masaki Fujiyoshi is a stay-at-home spouse and parent. He has fought long and hard with feelings of being a burden to his loving husband, Hiromu, due to his status as an omega—a secondary gender, allowing one to give birth regardless of if they are male or female—and the difficulty they faced to achieve this domesticity. When their son, Hikari, was born, the family moved to an area better suited for raising children.

Hikari is now nearing his second birthday, and he and his parents are forging meaningful bonds with those around them. These include the beta college student living next door, Yuuki, to whom Hikari has become rather attached; Hiromu's friend from work Matsuo; and the mysterious single dad seen wandering around the park.

Despite their newfound domestic bliss, the family's ties to their past are in tatters. There are people they left behind to pursue the creation of their happy family, and when they begin to return, Masaki and Hiromu are not quite sure they have good intentions.