Ui Ui

Ui Ui is a character in Jujutsu Kaisen. He is the younger brother of Mei Mei

Appearance
Ui Ui is a young boy with light colored hair with most of it that is parted to the left, and small thin eyebrows.

Ui Ui wears a light colored long sleeved button down shirt with a high collar, black shorts that are held up with black suspenders, black socks, and black shoes.

Personality
Ui Ui worships his older sister Mei Mei and acts as a type of lapdog for her. His loyalty for her is so great that he is willing to die for her, as seen when the pair fought against the Smallpox Deity. He also expresses distain to individuals who cause inconvenience to Mei Mei, or those who do not accept her compliments.

Shibuya Incident Arc
On October 31, Ui Ui is with his sister and Yuji at Aoyama Cemetery while Gojo handles the problem in Shibuya. When Mei Mei gets a call about a certain appearing at Meiji-Jingumae Station, Ui Ui along with Mei Mei and Yuji head out to check up on it. Once they arrive at Meiji-Jingumae Station, they are informed about situation that is happening at the station. After being informed, Ui Ui and Yuji wait by an entrance while Mei Mei uses her power to spy on what is happening in the station. When Yuji gets impatient, Ui Ui tells Yuji to calm down while his sister is checking out the station. Once Mei Mei is finished with her task, he listens as Mei Mei explains everything that is happening in the station. After listening to this, Ui Ui heads out with his sister while Yuji enters the station through a different entrance. When the curtain has been raised, Ui Ui informs his sister. The two then heads to B5F platform to wait for Yuji.

Once Yuji arrives at their location, the three head off to were the trapped people are at which Ui Ui carries his sisters axe along the way. While running, Ui Ui gets angry at Yuji for not accepting his sister compliment. Once they arrive at the station, they notice that only one person is there. Ui Ui, along with Mei Mei and Yuji, then head towards Gojo's location, but stop when Yuji is suddenly contacted by Kokichi Muta. Ui Ui listens along with Mei Mei and Yuji, as Kokichi what had happened to him and the situation that is happening in Shibuya. After Kokichi explains everything to them, Ui Ui decides to help his sister face off against the cursed users while Yuji heads back to help Gojo.

Once the cursed users get close enough, Ui Ui prepares to fight them along with Mei Mei and Yuji. After defeating one of the cursed users, Ui Ui watches as his sister defeats the other one. When Mei Mei defeats the other cursed users, Ui Ui informs his sister that the curtain has come down and the two head towards the station. After a while, Ui Ui and Mei Mei are confronted by Geto. Ui Ui then watches as Mei Mei deals with the cursed spirit that Geto had left them. When Mei Mei manages to figure out how Smallpox Deity's attack works, she asks Ui Ui to die for her which he agrees to. As Ui Ui raises his cursed energy to its max, Smallpox Deity seals Ui Ui in a coffin. Smallpox Deity tries to use his attack on Ui Ui, but is doesn't work since Ui Ui used simple domain to block the effects of Smallpox Deity's ability. Once Smallpox Deity is exorcised, Ui Ui and Mei Mei are released from the spirit's domain. Ui Ui and Mei Mei then prepare to face Geto.

Physical Power

 * Strength: Ui Ui has shown to be able to carry his sister's large ax even while running with his sister and Yuji.
 * Speed: Ui Ui is capable of keeping up with his sister and Yuji while they ran at full speed.

Jujutsu
Cursed Technique: It is currently unknown what Ui Ui's cursed technique is.

Sorcerer Techniques: These technique are ones that any sorcerer is capable of using.
 * Simple Domain: Is a type of domain technique that automatically neutralizes or counter all curse technique in a set area of space.