Voice Actor: Kyle McCarley (https://youtu.be/8IzO-qVmXso)

The main protagonist of Under Night In-Birth. A second-year high school student who was attacked by a Void on his walk back home from school. His life was saved by Linne, a strange girl he encountered a few days earlier. Having awakened as an In-Birth, he is taken under Linne's wing and begins training under her and her companion Waldstein, preparing himself for when the Hollow Night comes again. His association with Linne quickly earns him a reputation out in the night as the Unknown Actor, and later gains further notoriety by his possession of a particular blade. In his regular life, he is close friends with Orie, a childhood friend to Yuzuriha, and unknowningly becomes a rival to Seth.

Straight-forward and strong-willed, Hyde is an individual who gives his all to any challenge before him and doesn't back down from a fight. Although normally cool-headed, he has a cocky and reckless side to him and tends to head into extremely dangerous situations. Hyde has stated that he has no desire for power and only wants to live his life like a normal person.

Hyde is someone who greatly values his friends and comrades. Although he is capable of using Insulator to kill Linne, he decides to postpone doing so as he feels that she has much more to teach him. He was also hesitant to fight Orie due to the positive relationship they have and offers Vatista a place to stay until she completes her mission.