Episode 31

Evening Festival (宵祭り) is the thirty-first episode of the Jujutsu Kaisen anime adaptation and the seventh episode of the second season.

Summary
Ultimate Mechamaru and Mahito clash! Kokichi Muta must use everything in his arsenal to survive, including the massive Mechamaru Mode: Absolute. Ten days after the battle, the awaited Shibuya Incident finally begins!

Plot Details
Mahito survives a near point-blank Ultra Cannon from the massive Mechamaru and darts around the battlefield attempting to avoid the giant's punches and kicks. Kokichi is aware his usual methods of attack won't be able to damage Mahito's soul but he has a plan in mind. He activates a charge worth two years of cursed energy and unleashes Miracle Cannon on the body of water. Mahito avoids any lasting damage but his clothes are burnt off. He enlarges his fist and punches Mechamaru across the face, landing a powerful hit that shakes the cockpit. Kokichi is made painfully aware that any more of Mahito's offense could rip Mechamaru apart if the battle dragons on.

Kokichi plugs a mechanical tube into a port in the cockpit, loading a cursed technique into it. This technique charged tube is fired from Mechamaru's finger like a projectile that stabs into Mahito's shoulder. Under the assumption that Mechamaru can't damage his soul, Mahito disregards the attack until his entire left arm explodes. Kokichi capitalizes by having Mechamaru attack while Mahito is injured, sending him crashing through the forest with a kick from the giant puppet. Mechamaru attempts to follow up but Mahito changes into a hybrid-bird form and flies away again. Kokichi notices that Mahito changed his appearance to hide his injury, confirming for himself that the projectile was effective. Even Geto is surprised that Kokichi's strategy is working. Keeping up his relentless attacks, Mechamaru fires Pigeon Viola to pursue Mahito through the air, forcing the cursed spirit to flee and transform into several different animals as he runs through the forest.

Unaware of which attacks are injuring him, Mahito has no choice but to be more careful and ascertain which one injured him. Mahito severs electrical wires connected to Mechamaru's head but he's quickly countered and sent flying with another punch. Confident he can win, Kokichi loads another tube with technique charge and goes for the kill. Refusing to give up another inch, the injured cursed spirit suddenly expands his domain: Self-Embodiment of Perfection. Mahito assumes Kokichi thought he wouldn't use domain expansion in preparation for Shibuya and states ten days is plenty of time to recover. Believing he's won, Mahito turns away only for Mechamaru to stab him in the back with another loaded technique charge. Kokichi reveals that he was able to protect himself from the domain and injure Mahito using one specific technique that was loaded into the tubes, New Shadow Style: Simple Domain.

Mahito's body implodes and Kokichi appears to have exorcised him at last. Geto admits he's impressed with Kokichi's application of Simple Domain. Kokichi turns his attention to taking out the curse user but he celebrates too early when Mahito suddenly crashes through the cockpit of the giant puppet. A regular-sized Mechamaru appears in the cockpit to hold off Mahito while Kokichi prepares another tube to stab directly into Mahito manually. The cursed spirit dispatches the puppet and the two fighters attempt to land their last-ditch attack at the same time. Unfortunately for Kokichi, Mahito's hands touch him before he's able to land the finishing blow.

Meanwhile, at Kyoto Jujutsu High, Kasumi Miwa sits next to the "sleeping" Mechamaru puppet and expresses how she enjoys that the students have gotten closer since the Baseball Game. Miwa wants to get even closer to Mechamaru and promises to visit Kokichi's real body one day. However, unbeknownst to her, her beloved classmate has already met his untimely end. Mahito regroups with Geto and the ladder asks if the fight was more dangerous than expected. Mahito claims that he blew himself up on purpose to deceive Kokichi and there was nothing dangerous about it. With that "warm-up" out of the way, Geto and Mahito reveal that the final preparations for the Shibuya Incident have been concluded.

Ten days later, just after 7 P.M. on October 31st, a forty-meter curtain is lowered over Shibuya. It traps civilians inside and they're told they won't be able to leave until Satoru Gojo arrives. Several teams of jujutsu sorcerers are placed outside the curtain as a precaution. These teams include sorcerers such as Megumi Fushiguro, Takuma Ino, Kento Nanami, Nobara Kugisaki, Maki Zenin, Naobito Zenin, Panda, and Atsuya Kusakabe. Managers inform each squad of the situation and gives them their orders to standby and take out anything that gets past Satoru once he goes inside. There's no cellular signal inside the curtain and the civilians are trapped, but they're not currently in any danger. However, Kusakabe notes that there are definitely special grade cursed spirits waiting underground. Around 8:31 P.M., Satoru Gojo arrives and enters the curtain.

Locations

 * Mechamaru's Hideout
 * Shibuya

Battles & Events

 * Kokichi Muta vs. Mahito (Concluded)
 * The Shibuya Incident (Started)

Jujutsu
Kokichi Muta's Techniques
 * Puppet Manipulation
 * Ultimate Mechamaru
 * Boost On
 * Sword Option
 * Ultra Shield
 * Mode: Albatross
 * Ultimate Cannon
 * Ultimate Mechamaru Mode: Absolute
 * Ultra Cannon
 * Miracle Cannon
 * Pigeon Viola
 * Technique Charge: Simple Domain

Mahito's Techniques
 * Idle Transfiguration
 * Domain Expansion: Self-Embodiment of Perfection

Trivia

 * The anime-only scene where Ultimate Mechamaru battles Mahito is likely an homage to the final battle between Team Dai-Gurren and Antispiral from the anime series Gurren Lagann.