Noriko Yoshida

A young boy makes a promise to his dying mother to look after his abandoned step-sister at all costs. But the love between them grows so strong and profound, it threatens to tear them apart... (YesAsia)

Sae and Kouhei met by accident on a train when they were both high school students, and a relationship starts to form. Later, when Sae needs to leave Hokkaido to go to Tokyo for studies, the two of them attempted to have a long distance relationship. However, their bond is tested by multiple challenges facing the two of them. (en.wikipedia.org)

Asako determines to live her life with her own will after witness her best friend's divorce and former manager's death. (imdb)