"We're not related by blood, but we're real parents." Now that same-sex marriage has been legalized Nao and Ai, who have been lovers since college, decide to register their marriage and adopt a baby boy named Hiro. Nao is sensitive and cries easily, while Ai has a 'going my own way' attitude. The two polar opposites begin child-rearing while dealing with the ups-and-downs such as colic at night, the first day at a nursery school, and making friends with moms!