Dan Katō

Dan wears his pale blue hair long, falling all the way to his back, above a pair of dark green eyes. His clothing is the Konoha shinobi standard of his era, complete with forehead protector and the older, pocketless style of flak jacket. Once Kabuto brings him back through the Impure World Reincarnation, his sclerae turn black.

Dan is remembered as a fine, principled man devoted to Konoha and everyone in it. Family meant a great deal to him, and he made a habit of collecting his younger sister from the Academy, a kindness he later extended to his niece. Wise and honourable, he held a firm faith in justice and knew the history of the shinobi world well enough to feel real dread when he learned that Madara Uchiha had been reincarnated. Even with the five Kage marshalled against Madara, Dan doubted they could truly win, and pinned his hopes instead on someone shutting down the reincarnation technique before Madara could cut them down.

The turning point of Dan's life came with the death of his younger sister, after which he began pushing for every squad to include a medical ninja. Tsunade held the same conviction, and the shared cause drew the two of them together. As they grew close, Dan confided his ambition to become Hokage so that he might better shield Konoha's people, and Tsunade gave him her grandfather Hashirama's necklace as a token of luck and belief in that dream. His gift on the battlefield was the Spirit Transformation Technique, which let him leave his body as a living spirit to strike or seize control of an enemy, and he felled countless foes with it during the Second Shinobi World War. That same war claimed him. Gravely wounded in a fight, he lost too much blood for even Tsunade to save, and he died in her arms. Devastated, Tsunade took in Dan's niece Shizune as an apprentice and eventually walked away from the shinobi life altogether.

Long after his death, Kabuto Yakushi resurrected Dan through the Impure World Reincarnation to fight the Allied Shinobi Forces, sending him into battle beside Asuma Sarutobi and Hizashi Hyuga. Facing the First Division, he came up against Choza Akimichi and warned that his Spirit Transformation could only be stopped if he were sealed away first, prompting the shinobi to trap him behind a barrier. When Naruto's shadow clone arrived, Dan at first mistook the boy for Nawaki, so alike were the two, and was moved to hear that Tsunade had staked her faith in him. Realising his own dream and Nawaki's now lived on in Naruto, he smiled. He was shaken to learn of Madara's return and of Tsunade taking up the mantle of Hokage, and he urged Choza to hunt down whoever had reincarnated Madara rather than face the man head on.

When the reincarnation was finally released and his form began to unravel, Dan used the Spirit Transformation Technique to seize control of his own departing spirit. He reached Tsunade just in time to take over her body and shield her from one of Madara's blows. Speaking with her one last time, he thanked her for achieving all that he never could, told her to keep living because she was his dream made flesh, and kissed her brow before pouring the last of his chakra into her to restore her Strength of a Hundred Seal. His soul then returned to the afterlife. His loss left a lasting mark, since the blood he shed while dying gave Tsunade a crippling fear of the sight of it. Years later she refused Orochimaru's offer to revive both Dan and Nawaki, unwilling to trade two living lives for theirs, and her love for him never faded as she turned away Jiraiya's affections and every other suitor in the decades that followed.