Jūgo and the Curse Mark

Boruto and Sarada escape the cave to alert Konohamaru, who arrives with Mitsuki just in time to blunt Jūgo's assault. Jūgo, locked in a full cursed seal transformation and driven purely by bloodlust, shrugs off every attack and seizes Konohamaru to drain his chakra. A Rasengan to the face drops Jūgo, whose transformation partly recedes, and he wanders off leaving Konohamaru weakened on the ground. The genin trail him despite his warnings and find him collapsed near a lake teeming with birds, fully returned to normal. Konohamaru rejoins them with the Team 15 girls and Tosaka, spotting an injection device beside Jūgo. Tosaka examines the man against the afflicted birds and marvels at discovering an endangered species' natural home. When a corrupted bird strikes, Jūgo lifts its cursed seal, then silently hands Boruto the kunai he had used earlier.

The team carries the injured Konohamaru back but agrees to withhold the details until more is known. Wasabi frets that his wounds might have infected him like the birds, yet Tosaka's analysis of Jūgo's blood proves the man's seal differs from theirs. Mitsuki identifies the recovered device as Orochimaru's research, and Tosaka, having tasted it, calls it a potent tranquiliser, likely meant to suppress the cursed seal. Konohamaru orders Team 15 to fetch reinforcements while Team 7 shadows Jūgo. Watching him strain to contain a bird's seal within his own body, the group is moved by his devotion. Over repeated transformations Boruto keeps offering help, and when Jūgo cannot dose himself in time, Boruto administers the tranquiliser, gradually winning the man's confidence.

This is episode 99 of the Boruto series, part of the Jūgo Arc. Jūgo explains that infected birds show red eyes before turning violent, and the highly territorial species offers a clue to tracing the outbreak's source. The group encounters Land of Rivers researchers investigating the same attacks, but Boruto conceals Jūgo's involvement, reasoning the birds cannot be saved without him. On their return journey, Team 15 is ambushed by two siblings wielding a device that activates cursed seals, while a Land of Rivers researcher secretly reports on Jūgo. The episode uses the opening theme Lonely Go! and the ending theme Tsuyogari LOSER.