Sumire Fujita attends Shin Koshigaya High School as a student and baseball team member, specializing as a second baseman. She has long hair often tied in twin pigtails and brown eyes. Her surname Fujita derives from "wisteria" and "field/rice paddy," while her given name Sumire translates to "violet."

During baseball practice with teammate Ryou Kawasaki, their uniforms and field presence led Yomi Takeda and others to mistake them for upperclassmen. Sumire corrected this error immediately, introducing both herself and Ryou. Their practice showcased a competitive dynamic, highlighted by Ryou’s flashy diving catches. Onlookers initially interpreted their exchanges as strained, but this perception shifted when Sumire responded to Ryou’s practice injury. She demonstrated concern by physically guiding Ryou to receive medical treatment for her wounds, revealing a foundation of mutual care and support beneath their on-field rivalry.