Mitsuki's Disappearance Arc

is the ninth arc of the Boruto: Naruto Next Generations anime. It covers episodes 71 to 92. The arc focuses on Mitsuki leaving Konohagakure and his friends pursuing him. It is preceded by the Chōchō Arc and followed by the Naruto Shinden: Family Day arc.

Five Kage Summit
Mitsuki wakes up after dreaming of when Log and Orochimaru both orchestrated him to join either one of them, and becomes surprised he can dream. At Lightning Burger, Mitsuki tells his friends about having his first dream while wondering what to eat, and Boruto is surprised Mitsuki has never had a dream. When Boruto asks him, he confesses he never felt like rebelling against his parent. Shikadai and Inojin joins them, the former who has a chicken on his shoulder, and explains it became attached to him after it hatched during his mission. When Sarada and Boruto explain it imprinted on him, Mitsuki compares it to first seeing Boruto after deciding not to choose neither his brother nor his father. Sarada reminds Team 7 they have security duty for the Five Kage Summit. At the summit, due to the meeting's topic being about the Ōtsutsuki clan, the acting Kage invite Kakashi, Mei and A. Darui notices Ōnoki's absence, prompting Kurotsuchi to inform the shinobi her grandfather had travelled to Konohagakure with her, but slipped away, leading to them deducing he's sightseeing.

While keeping watch, Mitsuki asks Boruto if he ever felt like his thoughts weren't his own, and wonders if his attachment towards his friends is like the chicken imprinting on Inojin. Boruto dismisses his concern, saying they're not chickens. Boruto goes onto to telling his teammates a question Naruto asked him earlier, about what the hardest rock in the world is. Learning that Konoha shinobi are searching for Ōnoki, Boruto becomes excited as he's sure the Tsuchikage would know the answer to his father's riddle. Running into Ōnoki, he reveals he knows who Boruto and Sarada are, but not Mitsuki. Telling the Kage he needs to attend the summit, Ōnoki tells them he doesn't want to attend the boring meeting. Bortuo then asks Ōnoki his riddle, resulting in Ōnoki agreeing to tell the three if they show him around the village, which they agree to. At the summit, they discuss Urashiki, and Naruto states Sasuke has left to investigate, while Kurotsuchi is irritated by her peer's easygoing attitude.

While touring the village, a construction beam falls towards a villager, leading to Ōnoki using Dust Release to save them, resulting in him passing out from exhaustion. Waking up, Ōnoki mistakes Boruto for Kozuchi, and explains that he was Ōnoki's grandson who died in his youth. Fulfilling his promise to the genin, Ōnoki reveals the hardest rock in the world is the unbreakable will of shinobi. Ōnoki asks Mitsuki about his will, but the genin finds himself unsure and it being complicated.

Attack on Konoha
Mitsuki later returns to his apartment to find it had been entered, and notices a letter had been placed on his bed, which he decides to light on fire. The next day before dawn at Konoha's main entrance, Uō and Saō are attacked by two assailants. While the Konoha shinobi are losing in their fight, Mitsuki attacks Uō with Lightning Release. After sunrise, the site is turned into an investigation scene by the Police Force, and Kōtarō reports to Sai that the two guards had been in attacked and were in comas. While surveying the scene, Sai finds a forehead protector in the woods.

While Sarada and Boruto wait for Mitsuki in the village, they decided to go find him to tell Mitsuki they their mission was cancelled. Unable to find him, Chōchō informs the pair that all the village's jōnin were instructed to assemble in the Hokage's office. Boruto and Sarada tell Konohamaru that Mitsuki is missing, and questions why the jōnin had been ordered to assemble. Konohamaru states it's for a meeting in relation to the Five Kage Summit before departing. The two suspect him of hiding something, and go to Hokage's office to eavesdrop. Naruto discusses the earlier attack with Kakashi, Sai, Konohamaru and Shikamaru, during which Tsunade enters the office. Sai beings out the headband he discovered, leading to Konohamaru identifying it as Mitsuki's. A shinobi informs Naruto that they were ready for the investigation, prompting the group to leave for the medical department.

Trivia

 * Mistuki's Disappearance Arc is one of the longest arc in the Boruto anime series.