This darkness within me runs deep...what would I do if I didn't have this light that's like the sun...

—Volume 012, Story 055

Shuusei Usui (碓氷愁生) is the bearer of Kami no Me, God's Eyes. Shuusei, also part of the guardians, is Hotsuma's partner and childhood friend. He helps the police in solving crimes with his "sixth sense". Thinking before acting, Shuusei is quiet and sensitive, and his excellent grades make him a model student at school. But behind his proper demeanour, those small teasing comments and weak smiles, he hides severe self-esteem issues that cause him to pass many days barely eating or sleeping at all. While he is more delicate than most, this also makes him unexpectedly stubborn and courageous. With his high intelligence and tendency to think before he acts, he is a resourceful ally whose determination is surpassed by few and is in charge of creating plans if Takashiro is absent. Like Yuki, he was also a girl in his previous life.


Shusei likes to tease Hotsuma and avoids giving straight answers through this method, whereas he is usually silent or smiling when confronted by other people. Although he seems popular at school and generally liked by the Zweilt Guardians, he maintains a formal nature designed to conceal how he actually feels and thinks. He never shows negative feelings if he can help it, and keeps how increasingly hopeless he feels from Hotsuma about his situation. His reticence is self-harming and he grows more and more melancholy, to the point where other Zweilts and members of the Giou clan are often heard asking if he is well.

When it is later revealed that Hotsuma knows the true reason why Shusei lost to the Opast Ashley, Shusei reacts with open surprise and admits that he honestly wanted to die and that living on is something he can no longer do. This quiet admission helps his partner to understand how hurt Shusei has been feeling for a while and how far Shusei would go to ensure his partner's happiness over his own. After restoring their friendship, Shusei learns the importance of sharing how he feels and how to trust his partner more.

During the manga, and even the anime, there are hints that Tsukumo wants to be friends with him, but Shusei seems to be consistently distant, treating Tsukumo in a polite, pleasant manner which eventually lifts towards the end of the series. Here, Shusei is seen accepting an ice cream from Tsukumo in Twilight Mansion and promising to spend more time with the younger Zweilt.


Shusei is a very handsome and attractive young man with brown hair and golden eyes.

He is frequently seen in smart casual clothes during his role with the police and tends to wear more outfits when resting in Twilight Mansion. Like Tooko, he wears the red tie denoting a second-year student at the school they attend.

While the cast are all slim, Shusei is observed as being "frail" compared to the others and serves a defensive purpose in battle, with physical actions restricted to casting spells through crystal spheres and wielding two blades named "Kurai Kurou".


Shusei is Hotsuma's childhood friend and greatly admired by his partner for his individual brilliance. He seems to have played the piano from an early age, now acting as a member of the student council in addition to performing 'clairvoyant' duties for the local police and fighting for the Giou clan. However, he is modest about his strengths and achievements, mainly concerned with his partner's welfare. In the manga, it is said that Shusei was a girl in a previous life and Hotsuma and she were a married couple.

He never left Hotsuma's side, even when the boy was isolated from others at school, and appeared just in time to persuade when Hotsuma tried to burn himself to death. This event caused the indelible scars on Shusei's body, making Hotsuma realise how dangerous it is to wield God's Voice. While Shusei never regrets saving his partner's life, what becomes unbearable for him over time is the look on Hotsuma's face every time he sees the scars.

Although his background is never revealed much in the anime, in the manga he is seen as a burden to his parents, overhearing them discuss the fact that he was never wanted, simply born due to expectations his parents felt had to be fulfilled. 


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Hotsuma and Shusei after an argument.


Hotsuma Edit

His relationship with Hotsuma has a strong bond and he trusts Hotsuma with his life. Both of them are very close to each other and it is shown that they would rather die then not be able to be with each other.  In the manga, when the Zweilts are talking about the low number of guardians, Hotsuma mentions that he and Shusei have tried to have a child in their past life, as Shusei was a girl in his past life. Hotsuma is also seen to be quite protective of Shusei and when he is taken by Ashley, Hotsuma seems to be extremely upset and angry.

Tsukumo Edit

Shusei seems to be distant to Tsukumo but near the end the manga/anime Tsukumo is seen giving Shusei an ice-cream. This could suggest that they become friends later on since Shusei says that he would like to spend more time with him.


During a week-long class trip with only Toko and Shuusei, Toko tells Shuusei about the rumours about the two of them of being a couple, Shuusei asks Tooko if she wants to be his bride. Later, he lets her escape from the unknown creature claiming she had a better chance and that he wouldn't 'go down without a fight'.


Yuki Edit

In the beginning, Shuusei went along with Hotsuma's standoffishness to Yuki but after Yuki convinced Takashiro to let him risk his own life to save Shuusei, as Takashiro wouldn't hear of it, but due to Yuki's pleading he allowed it. Shuusei probably wouldn't have been alive if Yuki hadn't done this, which he is shown to be quite aware of and tells Yuki that he, "plans on putting my life on the line to repay this favour." He then bows before Yuki, swearing devotion to him.

Trivia and NotesEdit

  • His Birthday is January 5th.
  • He wears a ring on his index finger which matches the ring also worn by his partner Hotsuma.
  • In the manga, Shusei mentions having two girlfriends in the past, though nothing is known about them.
  • He fights using crystal balls that he mainly uses for supporting the others and a pair of short swords, called Kurai Kurou (Crime & Punishment), for offense.
  • He says ones that, without Hotsuma, he doesn't have a reason to keep living.
  • He has two giant moles on the inside of his thigh.


  • "Please use this life as you see fit." (To Yuki.)
  • "If you want to die, then take me with you!" (To Hotsuma.)