Asuka Kaidō is a 16-year-old high school student and aspiring idol from Osaka, born on December 1. Standing 175cm tall with dyed blond hair (naturally brown), blue eyes, and blood type A, he balances studies with a part-time bookstore job. His name, written 海堂飛鳥, combines "sea hall/temple" (Kaidō) and "flying bird" (Asuka).

Publicly, Asuka cultivates a cool, princely image during livestreams like "Kaido Asuka's Cruising Room," addressing fans as "Princesses and Princes" and accepting virtual gifts of baseballs, candies, and roses. Privately, he reveals sarcastic bluntness and tsundere tendencies—outward aloofness masking hidden care, especially toward his idol partner Kanata Ichigoya. He fears ghosts, avoids roller coasters, and enjoys baseball (despite limited athletic skill) and stage theater.

Asuka forms half of the duo ASCANA with Kanata. Their dynamic features mutual teasing, with Kanata highlighting Asuka's height, looks, and hot-and-cold demeanor as charms. They live together, share manager Riku Maeda (who recruited them), and maintain a respectful rivalry with senior idols LIP×LIP. After aiding fan Hiyori Suzumi at a concert, she develops a crush; he declines her bookstore date proposal to prioritize idol work but welcomes her future fan support.

Within the "Heroine Ikusei Keikaku" narrative, Asuka serves as Hiyori’s initial love interest; his rejection indirectly contributes to harassment she faces from LIP×LIP fans. This storyline role shifts to another character in alternate adaptations. Asuka retired as a virtual personality in late 2021.