Daigan heads the Azababu branch of the antagonistic Criasu Corporation. His early awareness of the android Lamia stems from his responsibility to halt Doctor Thanatos' experiments on the Somniums. He possesses a plump, middle-aged build, short curly black hair, a mustache, and a braided goatee tied with a red ribbon, wearing round glasses and green clothing with gold trim and shoulder spikes.

Initially uncontrollably arrogant and overconfident, Daigan constantly boasted of outperforming colleagues, claiming he could finish any task in five minutes, and displayed a cocky, dismissive attitude toward subordinates. Ordered by George Kurai and Listol, he confronts the protagonists alongside Doctor Traum. Before combat, Dr. Traum betrays and stabs him fatally. Though Cure Ange attempts healing, he vanishes temporarily.

Daigan later reappears, purified, working for Papple at a pool party. He thanks Cure Ange for trying to save him. Post-purification, his personality shifts significantly: he becomes supportive and forgiving, befriending Saaya (Cure Ange) and reconciling with the traitorous Dr. Traum. During a Halloween event, Listol tempts him to rejoin Criasu; Daigan wavers, summoning an Oshimaida to disrupt the festival. After the Cures purify the monster, Papple intervenes with tough encouragement, revealing his snacks were well-received, motivating him to stay with her agency instead of returning to Criasu.

In the climax, he assists battling Mou Oshimaidas and temporarily transforms into a Cure alongside other civilians to help purify George Kurai. Post-resolution, he travels to the future via Dr. Traum's train. Twelve years later, he works as a nursing assistant for Saaya, now a doctor.

His abilities involve summoning monsters: first drawing out a victim's negative energy with "Hope for tomorrow, begone! Negative Wave!", then materializing it into an Oshimaida or Mou-Oshimaida with "I'm ordering you! (Mou-)Oshimaida!".