Dai Takabayashi, a fourth-grade classmate and close companion of Licca Kayama, balances a brash exterior with steadfast loyalty. Secretly nursing romantic feelings for Licca, his jealousy flares toward Rui Makiyama, the college student she admires. Though abrasive, he prioritizes Licca’s safety, repeatedly stepping into perilous situations to shield her—efforts often eclipsed by the timely arrivals of the Doll Knights.

Hailing from a large, multi-generational household steeped in strict religious traditions, Dai chafes under the watch of his intimidating grandmother. Childhood responsibilities weigh heavily on him; he often shoulders chores after losing Rock-Paper-Scissors games, a testament to his role as the family’s reluctant errand-runner. Academically challenged, particularly in math, he clings to quirky misconceptions like Antarctica’s "hot climate," yet thrives on the football field with natural athleticism.

A pivotal shift occurs when he bonds with Doll Isamu, a reformed antagonist turned ally, cementing Dai’s place among Licca’s protectors in the Doll Kingdom’s conflicts. His obliviousness to classmate Sumire Shinohara’s quiet affection adds tension to their camaraderie, contrasting his acute awareness of Licca’s every move.

Dai and Licca’s bond teeters between snarky competition and heartfelt teamwork, their banter masking profound trust. While his unrequited feelings linger, subtle growth emerges in his courage to face escalating dangers, though his impulsive streak and fierce protectiveness stay unchanged.

Entwined with the Doll Kingdom’s lore, Dai is mythologized as Licca’s destined "prince," a role underscored by his blue Calling Ring—a counterpart to Licca’s pink and Sumire’s green—binding him to the magical struggle at the story’s core.