Sumi Shinazugawa

Sumi is a girl of small build and light skin, her dark hair gathered in a low bun with the bangs clipped back at the crown. She has a small face with large, round blue eyes and bears a strong resemblance to her mother. She wears a long light red kimono fastened with an orange sash.

Kind and considerate like most of her siblings, she once shielded her youngest brother's view during one of their father's violent fits. Deeply devoted to her mother, she fretted on the rare occasions the woman was late getting back. Curiously, her brother Genya later described her as both thoughtful toward their mother and something of a spoiled child, though whether he meant this seriously is unclear.

The daughter of Shizu and Kyogo, Sumi was one of seven children in the household, the two oldest being her brothers Sanemi and Genya. Their father was brutally abusive until he was eventually killed by others who despised him, and through his outbursts the children were often protected by their mother.

One night, after their mother failed to return, Sanemi set out to search while Genya stayed behind. When a knock came at the door, Sumi and several siblings rushed to greet who they thought was their mother, ignoring Genya's warning. Their transformed mother burst in and attacked, killing Sumi instantly.

Her death haunts both surviving brothers. During Genya's battle with Hantengu, facing what he believed was his own end, his life flashed before him and he recalled the loss of his siblings and mother. Much later, as Sanemi lay dying from his wounds, he saw Sumi and the rest of his lost family waiting for him in the afterlife.

The characters of her given name carry meanings such as longevity and beauty, while the family name combines ideas of immortality and a flowing river. Though written with different kanji, she shares a given name with the Butterfly Mansion servant Sumi Nakahara, whose name stirs memories of her in Genya.