When and how do people become “fathers” and “mothers”?

This is a story of family which conveys the message of parental love that is so important in the times we now live in.
During their time at university, Natsu Tsukioka and Mizuki Nagumo ended up going out and life was good for them. However, one day, all of a sudden, Mizuki told Natsu she wanted to break things off, and they went their separate ways. Seven years have passed since then, and Natsu has moved on, when he learns from an old university friend that Mizuki has passed away. The two never met again after she told him it was over, so it still doesn’t feel real to Natsu when he goes to attend the funeral. There he meets a young girl named Umi. Natsu cannot hide his surprise when he learns that the girl is Mizuki’s daughter. Mizuki’s mother also informs him that he is the father. When Natsu learns that Mizuki had given birth to their child without telling him, and she had been raising her alone, he looks back on the seven years Mizuki and Umi spent together…
We bring you a work that carefully depicts the love between people, and the story of a family.