Yoshimi Iwaki is a second-year student at Satogahama High School with dark yellow or blonde hair and pink or aubergine eyes. She stands 1.48 meters tall, weighs 43 kilograms, and has blood type O with a birthday on April 3. Her appearance features a scar and a school uniform ensemble including a tie, coat, cap, and gloves.

Overdramatic and hot-blooded by nature, Yoshimi struggles to decline requests. She channels this enthusiasm as the self-proclaimed captain of Satogahama High's unofficial cheerleading squad, a position unrecognized by the student council yet emblematic of her persistence.

Within the baseball association—later an official club—Yoshimi plays left field, bats left-handed, throws right-handed, and wears jersey number 7. Her investment in team dynamics once led her to orchestrate a confrontation between teammates Tsubasa Arihara and Tomoe Kawakita, luring them to the baseball field to resolve a misunderstanding through physical conflict. Though her plan aimed to mend team discord, other members intervened to halt the escalation.

Beyond athletics, Yoshimi performs in the idol unit Clutch! alongside Satogahama peers Chikage Honjo, Kana Tsukumo, Aoi Asada, Maiko Kurashiki, and Shizuku Tsukahara. The group delivers songs like "ALL FOR ONE★" and "Summer Soul...," reflecting her multifaceted involvement.