Tobirama Senju (千手扉間, Senju Tobirama), the Second Hokage (二代目火影, Nidaime Hokage; Literally meaning "Second Fire Shadow"), was the younger brother of Hashirama Senju (the First Hokage) and the granduncle of Tsunade (the Fifth Hokage) and Nawaki.
Tobirama was a member of the Senju clan along with his leader and brother the First Hokage, Hashirama. When, decades before the start of the series, Hashirama struck a peace treaty with Madara Uchiha, Tobirama helped them found Konoha. When the First died, Tobirama was appointed as the Second Hokage. He was responsible for establishing Konoha's organizational system by setting up various organizations, such as the Academy, the ANBU, the Chūnin Exams and the Konoha Military Police Force which he created as a sign of trust towards the Uchiha clan. However, according to Madara, the Military Police was actually established to distance the Uchiha from the government of the village and place the clan under a tight surveillance under the ANBU.
Tobirama trained a three-man team of his own, Team Tobirama, which consisted of Hiruzen Sarutobi, Homura Mitokado, and Koharu Utatane. During a mission in the First Great Shinobi World War, on which Team Tobirama performed with Danzō Shimura, Kagami Uchiha and Torifu Akimichi, they found themselves surrounded by twenty elite Cloud ninja, known as the Kinkaku Force. Tobirama, then realized that the only way any of them could escape alive was for one of them to be a decoy and sacrifice themselves; therefore having faith that he had trained his students well, he chose to sacrifice himself after he selected his prized student Hiruzen for the position of Third Hokage. Homura and Koharu would become Hiruzen's advisers. After giving the title of Hokage to Hiruzen, Tobirama went off to fight the enemies where he died a noble death in battle.
Personality From what has been seen of Tobirama, he had pride in his abilities involving water jutsu. He also had a sense of humor, even under stressful situations. Like his brother, Tobirama felt a great deal of loyalty to the village, and placed its well-being above his own. Tobirama was strong-spirited, and passionate.