TV-Series
Description
Daiki Asuka, known as Asuka Jr. among peers, attends St. Paulia's Academy as the son of Detective Tomoki Asuka. Insecurity over classmates mocking his failures against the phantom thief Saint Tail drove him to secure a mayoral badge authorizing his police assistance. To ensure he alone captured her, he obtained Saint Tail’s promise to send advance heist notices exclusively to him.

Socially, his blunt remarks frequently offend others, and he shows minimal grasp of romance or girls’ feelings. Pride wounded by Saint Tail setbacks triggers explosive reactions to teasing. Yet investigations reveal his determination, strategic planning, bravery, and intense focus. He dissects Saint Tail’s methods with keen observation to predict her moves.

He constantly argues with classmate Meimi Haneoka but worries about her passive endurance of hardship. Suspecting Meimi is Saint Tail after the Princess Rosa’s mirror incident, he projected his burgeoning romantic feelings for Meimi onto the thief. Close observation during heists shifted his goal from arrest to protecting Saint Tail from the role’s strain, recognizing her altruism despite his early mantra: "a thief is still a thief."

Conflict defines his dynamic with Rina Takamiya, a transfer student and police investigator fixated on capturing Saint Tail. Her unreciprocated romantic interest fuels friction, especially when she targets Meimi. To shield Meimi from Rina’s harassment, he bet that if Meimi was Saint Tail, he would date Rina; otherwise, Rina must cease interference. Saint Tail tricked Rina into losing.

His character arc redefines "catching" Saint Tail—from literal capture to safeguarding Meimi after realizing how little he knew her beneath her personas. An obsession to confirm her identity stemmed from craving relationship clarity, culminating in a love confession when he acknowledged his pursuit as an extension of those feelings. After Rosemary exposed Meimi and kidnapped him, isolation led him to ponder her motives. During Meimi’s rescue, Maju’s taunt that Saint Tail’s notices were "love letters" revealed Meimi’s unwavering support. He caught her mid-fall and metaphorically "caught" her by freeing her from the Saint Tail burden, ending her vigilantism.

Eight years later, he works as a private detective continuing Saint Tail’s mission to protect Seika City, using tips from confessionals implied facilitated by Seira Mimori. He guards Meimi’s secret, proposes, and they marry.