Yūichirō Hyakuya 「百夜 優一郎, Hyakuya Yūichirō」 is the main protagonist of the series. He is a member of the as well as 's squad in the . He, along with and a few others, possesses the "" gene, which is relevant to the forbidden taboo and the focal point of the story, "Seraph of the End."
He also appears in and .
Appearance
Yūichirō has medium length black hair which can be considered quite neat and messy at the same time. He possesses sharp green eyes which fall under his thick eyebrows. His eyes are large compared to most other male characters in the series.
At the beginning of the series, he is shown wearing his school uniform, with a standing collar that is black with teal trim. The collar and the top buttons of the jacket are unbuttoned, revealing is a white shirt underneath.
After joining the Demon Army, he wears the standard JIDA uniform which consists of a long-sleeved black coat with light green details including the which has a brown passing diagonally over his right shoulder and two rows of gold buttons on the front. Along with that, he wears a pair of white gloves and a white web belt with a gold waist-plate. He also wears the uniform trousers and black boots which go over the trouser's leggings. Yu keeps his sword on the left side of his hip. Sometimes he can be seen wearing the JIDA hat, and often wears the JIDA cape as well.
PersonalityHuman
Yu takes on the vampire
Yu is brave, fearless and somewhat reckless, which was shown when he attacked a while ignoring orders. It is noted that this wasn't the first time. Yu is often called an idiot by those who know him. He is a very narrow-minded person, whose only goal is to annihilate all vampires because of what they did to his "family," and he will overcome any type of challenge in order to accomplish it. He swore to exterminate all vampires for killing Mika.
Yu wakes up after a nightmare
Despite this, he has a soft spot and worries about his friends first and his goals second. considers this attitude to be "cute". Because of this, he empathizes with others who put their family first, as seen when a civilian girl gave his squad false information because vampires are holding her family hostage. After learning why she deceived them, he tells the girl that she did the right thing to save her family. He feels guilty for abandoning Mika and has nightmares about Mika's death for four years until he makes friends with Shinoa and Yoichi. After learning Mika is alive, Yu's personality changes in response and he grows more mature, as noted by Shinoa. He puts more effort into being patient and calm and making friends, and immediately amends his worldview to include Mika even though he is a vampire. His dream of wiping out vampires takes second place to reclaiming Mika. Regardless, even though his best friend is now a vampire, Yu still slaughters them without mercy or hesitation. After Shinjuku, he becomes closer to his squad members and makes Guren promise to help him take Mika back under the promise that Mika will be useful to him, as he comes from the same orphanage as Yu. Additionally, friendship and bonds become more important to him, as shown in a mental battle against Asuramaru, to gain more power or else lose his body, he calls Asuramaru his friend and convinces Asuramaru to yield to him.
Rather than revenge, his primary goal changes to protecting his new "family," in order to avoid a repeat of past events. In Nagoya, he surprises Narumi's squad by memorizing all of their names and promising to protect them.
Similarly to how vampires do not bother to remember human faces and only think of them as "humans" or "livestock," Yu only sees vampires as "vampires" or "bloodsuckers" without bothering to remember their names or faces. He does not even recall the name of his vampire target in Nagoya. The only exception to this rule is Mikaela Hyakuya, and seems to recognize Ferid Bathory.
