Tobirama Senju (千手扉間, Senju Tobirama) was a member of the renown Senju clan, who, together with his elder brother and the Uchiha clan, founded the first shinobi village: Konohagakure. Throughout his lifetime, Tobirama would work tirelessly to achieve political stability and implement the institutions that made the village system work, thus ensuring Konoha’s continuity and prosperity. After his brother’s death, he would succeed the title of Second Hokage (二代目火影, Nidaime Hokage, Literally meaning: Second Fire Shadow).
Tobirama was born during the Warring States Period, and was the second of Butsuma Senju’s four sons. He and his brothers grew up on the battlefield waging constant war with their rivalling clans especially the Uchiha. After the deaths of their brothers: Kawarama and later Itama, Tobirama and his older brother, Hashirama, decided a new shinobi system would need to be implemented to end the cycle of child deaths — a system that would require an alliance between the warring clans. At some point in time, it became apparent that Hashirama got into the habit of disappearing into the forest for extended periods, and as such, Tobirama accepted his father’s assignment to follow Hashirama and find out what he was doing.
From tracking Hashirama, Tobirama discovered that he was meeting with a boy named Madara: a young Uchiha. After Tobirama reported this to their father, Butsuma pressured Hashirama to lead Madara into an ambush to be carried out by himself and Tobirama. Upon springing the trap, however, they were met by Madara’s family — who had similar plans and while their fathers clashed — Tobirama fought Izuna Uchiha: Madara’s younger brother. Hashirama and Madara were able to negotiate a temporary ceasefire, allowing all of them to walk away without bloodshed. In the years following their families would continue to clash, Hashirama against Madara and Tobirama against Izuna. On one occasion Tobirama eventually mortally wounded Izuna.