Radiyu is a South Korean internet broadcaster and Virtual YouTuber who hosts variety gaming and radio talk shows. She calls her viewers 'Wong-wongies' and is greatly loved for her signature kid-like, cute voice and friendly charm. Her biggest characteristic is her real-variety style communication, where she bickers informally with viewers to create laughter. Although she sometimes appears clumsy, she shows off a reversal of charm with her excellent singing ability in her karaoke content, 'Raraoke'. She uses an avatar with white hair and navy blue clothing.

Yu Mira is a sub-character born from Radiyu's April Fools' Day reversal concept. Her name is derived from 'Yu-di-ra' (Radiyu spelled backward) and also stands for 'Radiyu Mad for YouTube.' She boasts an intense visual centered on crimson red, featuring black hair, red clothing, and red eyes that perfectly contrast with the main character's white hair and blue outfit. Her most prominent feature is her use of the 'Siriyu' tone—a mature, cold 'older sister' voice—which differs from her usual playful tone. She shows such incredible acting skills and spicy tension that it's hard to believe she is the same person as the main character, enjoying thick independent popularity to the point where viewers call her 'Mira-nunna'.

Radian is an AI-concept VTuber developed based on Radiyu. Unlike Radiyu in her navy outfit, Radian wears a blue skirt and has blue eyes. Her hair is closer to silver, and she features a barcode instead of a tear tattoo and an antenna instead of a pollack roe accessory. Her charm lies in calling humans 'lower organisms' and delivering relentless 'fact attacks' to viewers with high-dimensional logic. She uses a cold, mechanical tone that seems devoid of emotion, yet creates laughter with unexpected clumsy moments. Her signature meme is 'Self-Termination,' where she turns off the broadcast without notice once her goal is achieved or if she gets bored. She gained great popularity through her unique vibe and unrivaled tsundere charm.