Makie is a master swordswoman and Anotsu's love interest—and arguably his equal in combat. The two go way back; she saved his life as a child using skills that were frankly terrifying for someone her age. She comes from a samurai family, though that didn't last. Her father Harukawa disowned both her and her mother after Makie's older brother killed himself, unable to cope with the fact that his little sister had inherited the family's legendary sword talent and could beat him in a fight. It was humiliating for everyone involved.
For a while Makie tried to walk the path of vengeance—her mother's disgrace demanded it. But when Anotsu bought her freedom, she became a geisha instead. Partly that was practical; she didn't have it in her to become a prostitute like her mother did. Partly it was deeper: she realized she didn't have the killer instinct needed to be a real swordfighter. Her concentration breaks too easily in actual combat.
She defeats Manji at one point but doesn't kill him, and for a moment it looks like she's abandoned Anotsu altogether. Later she's found alone with her hand bound—a deliberate crippling, an attempt to destroy her own skill. That doesn't stick around, though. In Last Blood, she resurfaces, having tracked Anotsu since he left Shirakawa when she noticed his body deteriorating. She takes down Iriya's men and sticks with Anotsu and Magatsu after Iriya falls.
According to Anotsu himself, she's the only person who can actually beat him. Her weapon is a double-bladed three-section staff called Haru-no-Okina—the Old Man of Spring—hidden inside a hollowed-out shamisen. She first shows up in Dreamsong Part 1.
Content compiled by AnimeList.moe from publicly available sources.