When the Fang Clan threatened her village, she hired Kenshiro and Rei as mercenaries for protection. The Fang Clan attack resulted in the death of her little
Mamiya is a character from Fist of the North Star. The leader of a village, she bears a resemblance to Kenshiro's fiancee Yuria. Mamiya hires Kenshiro and Rei to protect her village from the Fang Clan. However, the Fang Clan managed to capture her brother Kou, her last remaining relative. Mamiya was initially attracted to Kenshirō, but he did not return her feelings. She helps Ken to find Toki, discovering that he is imprisoned at Cassandra. Rei falls in love with her and kills Yuda during his dying days to avenge Mamiya's honor. , and was forced to allow the clan to kill him, as the alternative was allowing the village to be sacked. She subsequently assists Kenshiro and Rei in their effort to find the Fang Clan hideout and eliminate them once and for all.
Mamiya subsequently helps Kenshiro find Toki, learning that he's being held prisoner in Cassandra.
On Mamiya's twentieth birthday, she was kidnapped by Yuda, a practitioner of Nanto Seiken with a demented obsession with beauty, and who also killed her parents before her eyes. While Yuda's captive, she was branded with his signature "UD" on her shoulder, but managed to escape and returned to her village three days later. She chose at that point to give up her womanhood to become a warrior.
After Rei is doomed to die in three days by Raoh's strike to one of his pressure points, Rei learns that Mamiya too is cursed by the Death Omen Star and also learns of her past with Yuda. Having fallen in love with Mamiya, Rei pledges a vow to end her suffering and dedicates what little time he has left to tracking down Yuda and killing him.
To respect Rei's last wishes, she Mamiya gives up her life as a warrior and embraces her womanhood. Mamiya later appears during the Gento arc and again during the final arc of the manga.