Three years have passed since the baby Ai returned to the future. Koume Asakura and her childhood friend and boyfriend Mao Hagino are now high school students, counting the days until they can see their future daughter again. One day, a strange disturbance at Koume’s house leads to a miraculous reappearance: Ai comes back through the mirror, now a little older and more independent, and she is not alone. In her arms is her baby brother Daichi, Koume and Mao’s future son.

The sequel follows the newly expanded four‑person family as Koume and Mao juggle high school life, part‑time jobs, and the everyday chaos of raising two small children from the future. Ai, now a curious and active toddler, constantly gets into mischief, while Daichi is a laid‑back, easygoing baby who adds his own brand of surprise to the household. Together they navigate school festivals, summer outings, cooking adventures, and holiday traditions, all while keeping the secret of the children’s origin from friends and neighbors. At the heart of the story is the warm, comedic bond that grows between the young couple and their unexpected children, as they learn what it truly means to be a family.