Season 1

Koharu is a single mother raising two children since her husband died in an accident. She tries to apply for public assistance at the welfare office.

A child custody officer suspects Koharu of abusing her children and advises her to place them in someone else's care. Koharu visits an old friend.

Koharu doesn't know how to react to Shiori's familial affection. Kentaro offers to take care of Nozomi and Riku while Koharu is at work.

The daycare teacher tells Koharu that Riku's quietness may be a developmental issue. Koharu takes her children to see the dogs at the park.

Koharu is diagnosed with a serious health condition and advised to carefully consider her treatment. Later, a surprise gift arrives at her apartment.

When Koharu pleads with Sachi to allow her and her children to move in, Shiori voices her approval. Koharu receives an unexpected item from Kentaro.

Koharu takes Nozomi and Riku to her late husband's hometown. The owner of a local souvenir shop gives her a letter written by Shin four years earlier.

Distraught by the revelation of Shiori's past actions, Koharu decides to leave the Uesugi household. Sachi is torn between her daughters.

While Koharu is in the hospital, Sachi spends some valuable time with her grandchildren. Later, Kentaro learns about Shiori's past with Shin.

Sachi goes in search of Shiori, who suddenly spots the man who pushed Shin onto the tracks. Nozomi visits the hospital where Koharu is being treated.

Sachi and the others can't help but worry as they wait to hear if Shiori's bone marrow is compatible. Yuki brings boxes of Shin's keepsakes.