Cursed Child Arc

The Cursed Child Arc (いの) is the story arc that covers Gege Akutami's Jujutsu Kaisen 0: Jujutsu High prequel series. It follows Yuta Okkotsu as he enrolls in Tokyo Jujutsu High and seeks to unravel the curse on his childhood friend, Rika Orimoto.

Enrolling at Jujutsu High
Yuta Okkotsu and Rika Orimoto made a promise to one another when they were young. That they would fall in love and marry one another when they got older. However, one day Rika died in a tragic traffic accident before their dream could come. Following her demise, Rika was cursed after death and became a vengeful cursed spirit that haunted Yuta all the way into high school.

After an incident in which Rika brutally mangles Yuta's bullies, he's apprehended by Tokyo Jujutsu High and the jujutsu sorcerer, Satoru Gojo. Rather than execute Yuta, Satoru presents the young man with the chance to enroll at the jujutsu school to learn to control Rika's powers and use them for good. Rather than die in total isolation, Yuta agrees to become a jujutsu sorcerer. Registered as a special grade cursed human, Yuta is permitted to attend Tokyo Jujutsu High as a first-year student.

Maki Zenin, Toge Inumaki, and Panda are the only other first-years at the school. They're not so fast to accept Yuta due to the nature of his condition. In order to get Yuta experienced quickly, Satoru assigns him a mission with Maki. They're tasked with finding missing children who've disappeared from an elementary school with proven paranormal activity. After casting a curtain, Satoru leaves his students to exorcise the curses at the school.

Maki is able to make short work of the first wave of curses, but they're both ultimately caught off guard by a giant curse that swallows them both hole. In the belly of the beast, the sorcerers find the two missing kids. However, their bodies aren't resistant to curses like Yuta's. Maki is susceptible as well and she decides to ask Yuta why he became a sorcerer. Yuta looks deep within himself and states that he wants to deserve to stay alive. Determined to prove his worth, Yuta puts on Rika's ring and calls upon her power. Rika's cursed spirit form is fully manifested, allowing Yuta to escape safely with everyone and complete his mission.

Following his successful test run, Satoru has Yuta train with Maki for several months following the mission. He gives Yuta a katana to channel his power and has Maki show him in how to use it with intense training. On his next assignment, Yuta goes with Toge to clear out a shopping center scheduled for demolition of any curses. Despite being enrolled at Jujutsu High for a while, Yuta is still unfamiliar with Toge.

During their mission, the initial wave of curses are swiftly exorcised by Toge's unique cursed speech technique. The mission appears to be over but another far more powerful cursed spirit appears to confront the boys. Toge's counterattack fails and they're forced to retreat. Only when they work together and trust in each other do the two young sorcerers manage to exorcise the curse.

Suguru Geto, the Worst Curse User
Impressed, Suguru Geto watches from above. He used all the aforementioned curses as a way to test Rika's power. Unfortunately for him, he wasn't able to see it in person. Kiyotaka Ijichi meets with Satoru after the mission and the latter confirms Suguru's involvement. Unbeknownst to them, Suguru begins planning on making his move. He plans on ending the age of non-sorcerers by crushing the pinnacle of the jujutsu world, Tokyo Jujutsu High.

Suguru invades the school grounds to confront Yuta directly. He commends Rika's strength and is quickly confronted by Satoru and Principal Yaga among other sorcerers. He uses the opportunity and attention to announce that on December 24, 2017, the Night Parade of a Hundred Demons will commence in both Shinjuku and Kyoto. One thousand cursed spirits will be unleashed in each city and ordered to murder all non-sorcerers. He leaves shortly after demanding both sides to curse each other to their heart's content.

Masamichi Yaga holds a meeting with all available sorcerers to plan a way to counter Suguru's upcoming terrorist attack. However, Suguru sees through his former mentor's plan. When the day arrives, all jujutsu sorcerers and the vast majority of students are present in either Shinjuku or Kyoto to fight. Suguru uses this to his advantage and infiltrates Tokyo Jujutsu High alone while Yuta is isolated.

Maki attempts to stop him and Satoru becomes wise to Suguru's plan, sending back Toge and Panda to stop him. Suguru defeats all three of Yuta's friends, grievously injuring them. After finding the curse user standing over his dying friends, Yuta loses control of his emotions and calls Rika out in a rage. Together they fight against Suguru and reveal their ability to copy cursed techniques. Using a reverse cursed technique, Yuta heals his friends and even copies Toge's cursed speech to repel Suguru's curses.

In the climax of their battle, Suguru puts all his curses into one attack: Maximum: Uzumaki. As a last resort, Yuta gives his heart to Rika and promises to spend his life with her no matter what. This removes the limits from Rika's power, giving them the power generated by the strongest curse of all: love. With this strength, Yuta defeats Suguru and forces him to retreat. The curse user doesn't get far, and meets with his ex-best friend, Satoru Gojo one last time.

Yuta prepares to devote his spirit to Rika in the afterlife, but suddenly her vengeful spirit form comes apart. Satoru arrives to reveal that the curse has been untangled and his role in cursing her in the first place. Yuta is a descendant of Michikaze Sugawara, a big-time sorcerer who became one of the Big Three Vengeful Spirits, meaning he's distantly related to the Gojo Family. When Yuta rejected and cursed Rika's death, his cursed energy caused her to manifest as a vengeful spirit.

Yuta expresses remorse for what happened but Rika assures him that her time as a curse was better than her time alive was. She says her final goodbye to Yuta, who decides to continue on as a special grade jujutsu sorcerer and remains by the side of all his new friends at Tokyo Jujutsu High.

Chapters

 * Chapter 0-1: The Cursed Child
 * Chapter 0-2: Blacker and Blacker
 * Chapter 0-3: Punishment for the Weak
 * Chapter 0-4: Bright Darkness