Raidō's little sister is a junior high school first-grader when her brother Shōta Raidō starts high school. She has short black hair and brown eyes. Her school uniform consists of a standard white sailor top, a navy blue skirt, white ankle socks, and black penny loafers.

She considers her older brother "sort of an odd guy," puzzled by his stoic expressions and unconventional behavior. Despite this critical view, she genuinely worries about his ability to make friends, revealing an observant and caring nature. Their sibling relationship features typical dynamics, including an incident where Raidō ate her pudding when she was younger, causing her distress.

Approximately 12-13 years old during Raidō's first high school year, she remains three years younger than him. This age gap holds consistent in later manga chapters, where she continues wearing the same junior high uniform while Raidō advances to his third year of high school. She is friends with Eru Aharen, Reina Aharen's younger sister.