Sango Himeyuri is the older twin sister of Ruri Himeyuri. She stands 152 cm tall with light blue hair typically styled in twin buns, blue eyes, and physical measurements of 76-56-78.

Possessing advanced technical skills, Sango contributed to developing next-generation maid gynoids for Kurusugawa Electronics. Despite this aptitude, she displays a naive and almost childish demeanor in social situations. Within the twin pair, Sango acts as the more proactive and advising sibling, frequently providing guidance to Ruri. Both sisters speak with a distinctive Kansai regional dialect.

In her interactions with protagonist Takaaki Kouno, Sango is open about her romantic feelings, contrasting with her sister's reserved approach. Takaaki assists her in arriving at school punctually and demonstrates kindness toward her. A notable moment occurs when Sango kisses Takaaki on the lips in front of Ruri and his friend Yuji, directly expressing her affection.