I met Shizuku, and I finally remembered. What kind of adult I wanted to be. The desire that I myself tried to run away from, to rebel against, to throw away…
—Nagi Arisuin
Nagi Arisuin
Nagi Arusuin as he appears the anime
Kana 有栖院凪
Romaji Arisuin Nagi
Gender Male
Age 15
Nickname/s Black Thorn
Arisu (Alice)
Black Assassin
Personal Status
Affiliations Hagun Academy
Akatsuki (former)
Rebellion (former)
Status Active
Blazer Status
Ranking D-Rank
Physical C
Luck D
Offense E
Defense D
Magic Cap D
Magic Ctl C
Voice Actor
Voice Actor Shintarō Asanuma (Japanese)
Chris Patton (English)

Nagi Arisuin was from an orphanage located in Eurasia with his best friend Yuuri who died soon after their counties' government officials and mayor hired a gang in order to kidnap all of the kids from the orphanage to clean up their streets. Nagi saved all the kids in the orphanage after killing the gang, but this caused them to become afraid of him. Afterward, he would later be known as the Black Assassin in Rebellion under the tutelage of the One-Armed Swordsman Wallenstein who killed the mayor for him. 

He is later sent to Hagun Academy as a first-student and spy for the Seven Stars Sword Art Festival as one of the students of Akatsuki Academy prior to his betrayal.


Nagi is a very effeminate looking man, having many effeminate features, like soft eyes, and very girlish lips, although this may be due to the fact that he believes he is a girl trapped inside a man's body. He has very long dark hair, that covers most of his forehead, and goes down all the way his ears.

He is usually seen wearing his Hagun academy school uniform as well. He also wears a religious cross, tied in with a necklace, around his neck.


Nagi is a very kind-hearted person who cares for his roommate Shizuku, constantly encouraging her and supporting her love towards her own older brother Ikki. He also seems to be very analytical, more so than he is leading on, as he analyzed Ikki and told him that Ikki's strength and his pain tolerance were the same things, even stating that it will someday destroy him.

The kind-hearted person, however, was shown to be just a persona of his, to trick the other students into believing that he was harmless when in actuality he is very cruel and doesn't even care about his supposed friend Shizuku, stating that she will still be done in.

Eventually, Nagi started to really care about Shizuku and the others as real friends, this would cause Nagi to betray Akatsuki and Rebellion.


Shadow Manipulation: Nagi's ability as a Blazer, Nagi can control shadows and use it to hide himself and his allies in it.

Master Assassin: As a former assassin of Rebellion, Nagi is a skilled assassin, being trained by Wallenstein himself. This gained him the nickname "Black Assassin". Nagi also possesses great skill in deceiving his targets, making them trust him, before stabbing them in the back.

Expert Combatant: Nagi is a skilled fighter, having defeated numerous opponents in the Hagun selection battles. Even as a child, Nagi was able to kill multiple adult men, ripping their bodies apart.


Nagi showing his device

Darkness Hermit

Darkness Hermit (黒き隠者): Nagi's Device. It takes a form of a dagger and grants him the ability to manipulate shadows. Nagi can materialize multiples of Darkness Hermit for his Noble Art.

  • Shadow Bind (影縫い(シャドウバインド) Shadou Baindo): Nagi's Noble Art. By stabbing his Device into another person's shadow, Nagi can bind his target's movement. Once the target is captured, their movement is completely sealed and is impossible to break.
  • Shadow Walk (日陰道, Hikagedou, lit."Shadow Path"): A Noble Art, that lets Nagi travel through shadows. There is a limit to the distance that Nagi can travel with the technique, but within that limit, Nagi can travel to any shadow he wishes to.
  • Shadow Spot (lit. "Hermit's House"): A hidden room, made from the space between shadows, that Nagi can enter anytime. He can also let other people in it. It's shaped like a small living room and has gas and water.
  • Shadow Beast (lit. "Animal Caricature") is a technique, where Nagi summons different kinds of shadow creatures from pools of shadows. So far, he has shown being able to summon shadow tigers and bears.


  • Nagi refers to himself as "a maiden born in the body of a man".
  • He's the second person Shizuku Kurogane opens up to besides her brother.
  • Nagi is very knowledgeable about fashion.


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