Koku, B: The Beginning Wiki

Koku is one of the protagonist in B: The Beginning. He works as a Violin Craftsman under Lily's father and has the ability to transform into a black-winged, heteromorphic being. He is also the true identity of Killer B, a name derived by his unusual way of writing the number "13" at his murder sites. Since the attack on Jaula Blana orchestrated by Gilbert Ross that took the lives of several of his classmates including Dr. Heath Flick, Koku has spent the last seven years in search of his love, Yu

Koku (B: The Beginning) vs Elsa Granhiert (Re:Zero) - Battles - Comic Vine

B: The Beginning Succession

Koku [黒羽], Wiki

Anime Society

The Case Study of Vanitas ep.2 - There's Always a Jeanne

B: The Beginning The Sequel - This Week in Anime - Anime News Network

Koku Anime-Planet

Koku, B: The Beginning Wiki

Koku, B: The Beginning Wiki

Koku, B: The Beginning Wiki

B: The Beginning (TV Series 2018–2021) - IMDb