Kiriko Endou

Kiriko is Kenji's older sister and Kanna's mother. For the vast majority of the manga, Kiriko is only seen in flashbacks, where she is shown to have a strong sense of justice and an interest in biology. She was also an important mother figure for Kenji during his youth, often taking him places or getting him presents and helping him out (like when he was hospitalized due to a motorcycle accident or when she got him an electric guitar).