Hikari latches onto the reluctant and gloomy neighbor boy, Yuki. Later, when Masaki falls ill and needs to isolate himself, Hiromu and company try their best to distract Hikari from "Ma-cha's" absence.

Hiromu's disapproving father Koji shows up at the house unannounced, when Hikari the hero swoops in to protect his parents! But when it becomes apparent that Koji's visits have another agenda, can Hikari the hero save his family again?

As the family prepares for their second child, Hikari gets excited for his new role as big brother, but Masaki is overcome with worry over his new child's future. Later, the family plays hide and seek at Hiromu's family home.

Masaki gathers his courage and brings his family and friends with him to his hometown, but things get awkward when he's confronted by his cousin Kazuhiko.

Mayhem ensues when Matsuo's younger twin brothers Yuto and Shuto drop by for a visit. First they zero in on befriending Hikari, then they set their sights on Yuki and his relationship to their older brother.

Yuki tries to sort out his feelings toward Matsuo. Mochizuki finally gets the chance to meet Hiromu, but the meeting doesn't exactly go as nicely as Masaki was hoping it would.

After talking it out with Hiromu, Masaki attempts to reach out to Mochizuki and reach an understanding between them.

Hikari tries to be a good big brother to Hinata, but works a little too hard. Hiromu's parents try to make up for the years they've lost with their son and his family.

Masaki and Hikari encounter another new neighbor at the park: single father Mochizuki, who is trying to hold things together for his son Michiru after the loss of his spouse. Masaki offers to help.

Hikari wants to befriend the new neighbor's dog, but first he has to stop being scared of him. The family visits Masaki's uncle again, and Kazuhiko awkwardly tries to make conversation with Hiromu.

Masaki settles things with Kazuhiko, then takes his family to visit his parents' grave. Later, Hikari ventures forth on a new adventure: a solo errand.

A visit to Hiromu's office leads to an awkward situation for shy househusband Masaki, but baby Hikari continues to be a soothing presence in their lives. At Christmastime, Hikari becomes fascinated with the star at the top of the tree.