The November issue of Shogakukan's Monthly Flowers magazine revealed on September 28 that Akimi Yoshida's Umimachi Diary manga series will have an "important announcement" in the magazine's December issue on October 28.

The manga's story takes place in Kamakura, and revolves around Yoshino, the middle of three sisters. One morning, after she wakes up in a man's room, her father's obituary is delivered to her. Yoshino hadn't met her father in a long time, since her mother divorced him. After not seeing him for so long, she doesn't know how to feel at the announcement of his death. Only at her father's funeral do the sisters meet their half-sister whom they had never met.

The Umimachi Diary (Seaside Town Diary) manga began serialization in Monthly Flowers in 2006, and Shogakukan shipped the eighth compiled volume on April 10. The manga was a nominee for the 11th Cultural Affairs Media, Art, & Manga Award, and it won the 2013 Manga Taisho (Cartoon Grand Prize) award.

The manga inspired a stage play, which ran from March 31 through April 2 in Tokyo.