Hailing from Hokkaido potato farmers, Nono Daichi nurtured a passion for performing from childhood. Her carefree and excitable nature sets her apart, showcasing a more childish, energetic demeanor than typical idols; she often acts impulsively and expresses unrestrained joy, especially when meeting idols she admires. She frequently peppers her speech with Hokkaido dialect words like "namara" (very) and "menkoi" (cute).

Physically, Nono possesses long sandy-blond hair typically styled in twin pigtails secured with pink scrunchies, pink and purple heterochromatic eyes, and a distinctive beauty mark beneath her right eye. Her idol journey ignited after attending a Luminas concert during their Hokkaido tour alongside her childhood friend, Lisa Shirakaba. Inspired by Luminas and Lisa's resolve, she pursued training at Starlight Academy. For their audition, she and Lisa used Dolly Devil brand Aikatsu Cards, overcoming initial hesitation about the flashy designs to gain admission.

As a student, she specialized in the Dolly Devil brand with Lisa. Early on, they secured a performance slot at the Urban Girls Collection but required Premium Dresses. Traveling to Dolly Devil's headquarters, Nono became separated from Lisa and accidentally stained a stranger's dress. After helping clean it and reuniting with Lisa, they discovered the woman was Lucy Kisaragi, Dolly Devil's top designer, who crafted Premium Dresses for them inspired by the encounter.

Her foundational relationship with Lisa Shirakaba remains central; they are childhood best friends who staunchly support each other's idol activities. Mobile game content features them as the unit Nori Nori Sisters. Her family includes her father, Yutaka Daichi, and younger brother, Minoru Daichi. Reflecting her agricultural roots, her favorite foods are nikujaga (meat and potato stew), milk, and dried potatoes. Karaoke is her noted special skill.