Di-air is a seven-year-old female human with blue eyes and yellow hair, distinguished by her unique red hair clips resembling animal ears, which she can deliberately twitch. Her origins remain a mystery, lost to her own memory and hinted at being a past of "perpetual darkness." Recruited as an ES member candidate within the Galactic Trade Organization (GTO), she serves as an apprentice under Ascoeur and Q-feuille.

Her primary ability allows her to amplify the powers of others through direct lip-to-lip contact, significantly increasing the effectiveness and scope of their skills. This amplification enhances Ascoeur's teleportation for faster, larger-scale movement and refines Q-feuille's foresight into precise predictions. Di-air also possesses latent abilities for both time manipulation and spatial distortion, though the mechanics are unexplained. Given her age and powers, in-universe speculation suggests she might be a clone or reincarnation of Eclipse, the former director of the GOTT (Galactic Organization of Trade and Tariffs), though unconfirmed.

Di-air shares a close bond with T.A.M.A., a pocket-sized guarding robot that acts as her protector. Powered by her kiss, this robot can temporarily transform into a larger, combat-ready form. She often expresses childlike affection, such as enjoying physical cuddles from Q-feuille, and relies on her mentors for guidance during missions. Over time, Di-air evolves from a passive amplifier to occasionally employing her own time-space abilities in critical moments, signaling growing control over her potential. Her interactions with Ascoeur and Q-feuille contribute to their character developments, particularly in resolving conflicts involving memory manipulation or external threats.