Birthday: August 12
Daiki Asuka is a fourteen-year-old boy at St. Paulia's Private School, and is a top student in his class. His physical strength and motor skills are lacking.
Called Asuka Jr. by his classmates, Daiki Asuka is the son of Detective Tomoki Asuka. Because his father has been unable to catch Saint Tail, and doesn't place any emergency on this thief's capture, Asuka Jr. takes to task. He plans to one-up his father by catching Saint Tail.
After his getting close enough to photograph Saint Tail, Asuka Jr. is awarded a badge from the mayor, which allows him to go anywhere to investigate. With this, he is able to assist the police in Saint Tail's capture. Asuka Jr. is given notice beforehand of Saint Tail's crimes, at his own request. As she slips away from him caper after caper, Saint Tail becomes the object of Asuka Jr.'s thoughts.
Very dense about relationships, Asuka Jr. fails to see Meimi's growing feelings for him. He often argues with Meimi (whom he calls Haneoka), over Saint Tail and his inability to catch her. Asuka Jr. begins to think of Meimi when he sees Saint Tail, and viceversa, and is torn between which of the two he's falling in love with.