Pai Kawahigashi is Nashiko Jippensha's childhood friend and a central character. Born on August 1, her name draws from mahjong: "Pai" signifies tiles, "Kawa" the discard area, and "Higashi" the east wind. Gentle, kind, and cheerful, Pai possesses a healing, soothing presence with a relaxed, fluffy aura. She adores cute things and maintains an easygoing attitude, though she becomes energetic and lively outdoors.

Her strong family ties involved frequent childhood barbecues and trips, equipping her with practical outdoor skills. Pai demonstrates dexterity creatively, like shaping carrots into rabbits for curry. Apple pie is her favorite food.

At the mahjong parlor, she contributes positively using her knowledge of the rules and calm demeanor. Pai joins group activities beyond mahjong, including beach trips, training camps, festivals, and holiday celebrations. She approaches mahjong casually, prioritizing fun over competition. Online, after finding variations of her name or favorite food taken, she adopts the playful username "Super Surprised Apple Pie!", reflecting her persistence.

Throughout the series, Pai remains a consistent, supportive presence within the friend group. She engages in shared experiences blending mahjong with daily adventures, with her development emphasizing her role in fostering group cohesion.