A 28-year-old man. He works for a printing company called Ibata Printing. His parents divorced when he was three, and he was raised by his mother. He struggles to put his feelings into words and is easily influenced by those around him.

A 30-year-old woman and Ren's current girlfriend. She works in the development department of a cosmetics manufacturer. She has a serious and meticulous personality.

Yamato Tsukioka A 25-year-old man. Ren's younger brother. He lost his biological mother at a young age and became brothers with Ren at age seven when his father, Kazuya, remarried. Kazuya Tsukioka A 56-year-old man. Ren's stepfather. Yukiko Tsukioka A 54-year-old woman. Ren's mother.

Mizuki Nagumo A 27-year-old woman. The mother of Guest, Umi, and Koumi, and Ren's former girlfriend from their time at Seijo Meise University. She had a relaxed pace and worked at a library before she passed. For a certain reason, she decided to break up with Ren and dropped out of university, raising Guest, Umi, and Koumi with the support of those around her before passing away at a young age. According to her gravestone, she was 27 years old. Umi Nagumo A 7-year-old girl in the 2nd grade of elementary school. Mizuki's second daughter and Akane's granddaughter. The girl Ren met at Mizuki's funeral. It is revealed that she is actually Ren's biological daughter. Like Guest and Koumi, she is pure and innocent. She wears her black hair in pigtails. Akane Nagumo A 70-year-old woman, Mizuki's mother, and the grandmother of Guest, Umi, and Koumi. Though she and Mizuki sometimes clashed or misunderstood each other, she poured all her love into her daughter and watched over her as she decided to raise the children alone. When news of Mizuki's death arrived, she wept in front of Mizuki's memorial photo and altar at home, grieving the death of her precious only daughter. Shohei Nagumo A 67-year-old man and Akane's husband. Koumi Nagumo A 6-year-old girl in the 1st grade of elementary school. Mizuki's third and youngest daughter, and Akane's granddaughter. The girl Ren met at Mizuki's funeral. It is revealed that she is actually Ren's biological daughter. Like Guest, she is pure and untainted. She has an angelic smile, completely innocent and naturally oblivious to the world's impurities. She has a black hair in a short cut.

Mizuki's workplace during her lifetime. Seimei Tsuno A 32-year-old man and Mizuki's colleague. He fully supported Mizuki in raising her children. He harbors complex feelings toward Ren, the father of Guest, Umi, and Koumi. Meiko Mishima A female librarian. An older-sister figure who looks out for Tsuno and Umi and watches over them kindly. Toshiki Maeda A young male librarian and Tsuno's colleague.

Ayako Mitani A woman and Yayoi's junior at work. Natsumi Nogi A woman and the homeroom teacher at Kamomiya Elementary School in Odawara, which Umi and Koumi attend. Hiroto Fujii A man and Ren's colleague at work. Shiori Koide A woman and Yayoi's senior at work. She has two children.