Eighteen-year-old Japanese pop idol and actress Hatoko Daikanyama balances a public music career and noted acting struggles, including a professionally criticized incident where she refused to eat shitake mushrooms on set, leading to an emotional outburst against her manager and co-star. Secretly, she operates as the villain Dark Pigeon within Takashi Ryuugasaki's team alongside Jun Gotokuji and Miyama Soshigaya. Her public and villainous lives remain separate initially, concealing her connection from ardent fan Tsugumi Higashijuujou until later.

As Dark Pigeon, she confronts the Cyber Team in Episode 5 ("Basilisk"), luring Hibari, Suzume, and Tsugumi into a trap during a Pata-Pi contest using homunculi disguised as her concert audience to ambush them and attempt to steal their Pata-Pi devices. She summons her avian battle avatar, Cockatrice, attacking with aerial maneuvers and mouth lasers. After Cockatrice's initial defeat, she adopts the advanced Beelzebub combat suit, summoning two laser-firing pink pigeons, "Cuckoo Number 1" and "Cuckoo Number 2," to incapacitate opponents like the Diva Hestia.

Following Takashi's disappearance and the primary antagonist Crane's defeat, she abandons villainy with Jun and Miyama, forming the heroic Sibyl Team of Akihabara. In the series finale, she publicly reveals her dual identity to Tsugumi by singing her signature song, shocking Tsugumi with the connection.

Physically, she possesses long orange hair styled in two ponytails with a full fringe and green eyes. Her idol attire features a red and white tube dress with pink accessories, while her Dark Pigeon guise includes a pink-feathered black bomber jacket, skirt, thigh-high socks, and a wing-shaped mask. The Beelzebub suit combines pink, black, and white armor with a matching helmet. She shares a romantic interest in Takashi with Jun and Miyama.