Shimamura Imouto

She is Shimamura Hogetsu's little sister, attending elementary school while presenting a well-behaved front to the world. Behind closed doors, however, she reveals a playful and sharp-tongued side that few get to see. Though she tends to clam up around unfamiliar faces, she harbors an intense attachment to her older sister, making her a quintessential sister-obsessive. She has formed a close bond with the mysterious alien girl Nagafuji Yashiro, and the two are often found playing together. With the unfiltered honesty unique to children, she keenly observes the budding relationship between her sister and Adachi, never missing a chance to deliver a candid and biting commentary.