Hidarin, a supporting character introduced in the third season, is the drummer and backing vocalist for the all-girl idol pop group OTMGirls, consistently positioned on the left during performances. She sports gray-and-white fur, large black pupils accented by a single curled eyelash above each eye, and rosy pink cheeks. Three strands of her hair are pulled back with a white-and-pink plaid bow, mirroring the schoolgirl-inspired ensemble that includes a central plaid bow, a skirt, long white socks, and shoes.

Bubbly and spirited, Hidarin radiates cheerfulness, though her intellectual sharpness takes a backseat to her emotional intuition. She keenly discerns others’ feelings and motivations, balancing her lively demeanor with quiet perceptiveness. Her bond with twin sister Migi anchors many interactions, showcasing their close-knit dynamic. Occasionally, she drifts into playful daydreams, infusing her presence with a touch of whimsical charm.

Her name originates from the Japanese term *hidari* (左), meaning "left," a nod to her steadfast placement within the group’s formations.