Miwa Motegi, a first-year student at Matsuoka Girl's High School, shares classes and camaraderie with Fumi Manjōme, Yōko Hon'atsugi, and Misako Yasuda. Her enduring middle-school bond with Yōko and Misako is reflected in their affectionate nicknames: they call her "Mogii," while she addresses them as "Pon-chan" and "Yassan." Gentle and kind by nature, Miwa has brown shoulder-length wavy hair, black eyes, and stands 155 cm tall, consistently dressed in Matsuoka's uniform of blouse, tie, skirt, and knee-high socks.

She actively participates in Matsuoka's small drama club alongside Yōko and Misako, engaging in theatrical pursuits. Her commitment extends beyond her school, collaborating with Fumi to assist Fujigaya Girls' Academy during their cultural festival performance of *Wuthering Heights*. Advancing to her second year, Miwa faces class reassignments that separate her from her close friends, yet this shift does not fracture their friendships or disrupt club involvement.

During a summer trip to Kyōko Ikumi's family villa, Miwa meets Shinobu Okudaira, Akira Okudaira's older brother, sparking romantic feelings. Her interest deepens steadily, culminating in a confession later that year. By the end of her first year, she and Shinobu begin dating, establishing an ongoing relationship that persists into her second year. Akira observes this development with awkwardness but refrains from interference, cementing Miwa's romantic ties as a defining facet of her high school life.