Yuito Kisaragi serves as student council president at St. Cherine Academy, where his handsome appearance makes him one of the school's most popular boys and inspires romantic feelings in Haruka Minazuki. Despite his wealthy background, he takes various part-time jobs, including odd or occasionally humiliating roles. Secretly, he operates as the phantom thief Misty Knight, providing timely interventions and off-screen support to the Twin Angels during battles, drawing direct parallels to Sailor Moon's Tuxedo Mask. As Misty Knight, he wields blue roses folded from paper, with his special attack Rose Needle capable of piercing metal.

In Twin Angel: Twinkle Paradise, he appears to perish in an explosion during episode ten but resurfaces alive in episode twelve. During Twin Angel Break, he is identified as Sumire Kisaragi's older brother and shifts focus to rescuing the missing original Twin Angels, Haruka and Aoi, while thwarting Mary's energy-coin collection. Between episodes 5 and 6, he seemingly falls under Mary's brainwashing to attack people for coins, but episode 8 reveals this as a ruse to infiltrate and sabotage her operations.

Physically, he stands 181 cm tall, weighs 61 kg, and sports short teal hair. His role in the visual novel Kaitou Tenshi Twin Angel ~Toki to Sekai no Labyrinth~ remains a side character consistent with his established persona.