Satsuki Kururugi, a spirited 16-year-old idol, forms one half of the twin unit Twinkle Bell. Born on New Year’s Day, his 172 cm lean frame and 54 kg weight complement his striking appearance—pale beige hair with a right-side pink streak, pale blue eyes, and blue-rimmed glasses. His name, 皐月 (May), nods to his birth month, while his surname 枢木 blends "pivot" and "tree."

Known for his mischievous grin and boundless energy, Satsuki thrives on pranks, especially those provoking dramatic responses from targets like Akio Tobikura. He wears his heart on his sleeve, brushing off criticism with a carefree shrug. His world revolves around twin brother Mutsuki—their unbreakable bond forged from birth forms the core of their "two-in-one package" dynamic. Together, they channel "Miracle Power" through perfectly synchronized idol performances.

Declaring himself Twinkle Bell’s leader, Satsuki commands attention through flashy stage acts and playful mischief, though Mutsuki subtly reins him in when needed. Between gaming sessions and chocolate indulgences (he shuns corned beef), he strategically cultivates "sexual appeal," balancing cheeky charm with calculated idol magnetism.

Though his family background extends no further than unnamed parents and his twin, Satsuki’s drive stems from craving the spotlight and crafting unforgettable moments alongside Mutsuki. His portrayal remains steadfast across adaptations, anchored by three constants: trickster antics, unwavering brotherly devotion, and unfiltered authenticity.