Yahaba is a pale man with short black hair and red eyes which he normally keeps completely shut. His most unique trait is the pair of morphed green eyes on both palms of his hands that allow him to cast unique spells.
Yahaba dons a black and yellow kimono with a brown sash. He also sports a blue pearl necklace and white socks with sandals.
Yahaba is a loyal demon serving to please Muzan. Like Susamaru, he desires Kibutsuji's approval and the chance to become one of the Twelve Demon Moons. While he has a sadistic personality, Yahaba prefers to do things in a clean and mature manner. He dislikes Susamaru's immature attitude and hates getting himself dirtied.
Even in death, Yahaba regrets being unable to win Kibutsuji's approval and desires only to vindictively slay Tanjiro for rubbing his face in the ground.
Outraged by the appearance of a Demon Slayer wearing hanafuda-like earrings in Asakusa, Muzan Kibutsuji summons two of his followers to hunt him down. Yahaba and Susamaru walk the quiet streets during the night and pick up the Demon Slayer's trail. Yahaba uses his Blood Demon Art to track the hunter's movements and finds that there are two more people traveling with him.
Excited, Susamaru asks how the two should kill them all. Yahaba replies that they should kill them vindictively for their Lord Kibutsuji. He leads Susamaru to their enemies' hiding spot and she destroys a cloaking seal over the house using her deadly temari balls. Yahaba asks her how she plans to kill them and the Temari Demon agrees they have to kill them all vindictively. 
Susamaru destroys the house piece by piece using her temari. While she's enjoying handball, Yahaba notices the Demon Slayer is accompanied by three demons. He tells Susamaru she's too immature and to stop splattering dirt on his kimono. She simply tells him to get back and to calm down, having exploited their enemies inside the house.
Yahaba takes a supporting role in the assault, hiding up in the trees away from the action. He uses the Koketsu Arrows to guide Susamari's temari, tearing up the house and even managing to take off the head of the young demon boy, Yushiro. Yushiro eventually recovers and informs Tanjiro that Yahaba is using arrows to guide the balls unnaturally.
Tanjiro sends Nezuko into the trees to stop Yahaba. She finds him and delivers a powerful kick, but he blocks it and sends her flying away with a Koketsu Arrow after telling her to stop stirring up dust. Yahaba leaves the trees and Kibutsuji's followers stand off with their four opponents.
Tanjiro takes on the Susamaru alone while the others fight Susamaru. He smells an opening thread on the Arrow Demon but it snaps as soon as Yahaba activates his ability. He sends Tanjiro flying around, making him crash into the ground and multiple trees. Yahaba recognizes one of the others as Lady Tamayo the Fugitive and swears to bring Kibutsuji her head as well. Susamaru asks if they can bring Kibutsuji four heads but Yahaba says they only need two.
Yahaba forces Tanjiro on the defensive with his arrows and wraps one around his arm. Tanjiro flips in the direction of the arrow to avoid losing his arm. Yahaba believes he has control of the battle and calls the Demon Slayer a monkey for his acrobatics. Annoyed, Yahaba unleashes more vector arrows that Tanjiro finally counters by enveloping them in his Water Breathing techniques and using the momentum to direct his attack.
The Arrow Demon tries to force Tanjiro away by activating his arrows, but only manages to make his sword extremely heavy. Even so, Tanjiro manages to slash the blade and decapitates Yahaba with Later Water Wheel.
Slowly disappearing, Yahaba laments his inability to win Kibutsuji's approval. He curses Tanjiro for rubbing his face in the ground and decides to take him out with him. Yahaba's body places Koketsu Arrows on Tanjiro from all directions as a parting gift. Tanjiro manages to avoid being crushed by unleashing consecutive swordsmanship techniques one after the other. Yahaba disintegrates before being able to kill the him, but manages to take him out of the rest of the fight. 
Abilities and Powers
Yahaba's signature fighting style utilizes his Blood Demon Art: Koketsu Arrow from long range. It is particularly efficient when used in conjunction with Susamaru's Temari. Together, they were able to flush Tamayo the Fugitive out of hiding and destroy their hideout.
Blood Demon Art
Koketsu Arrow (紅潔の矢): Yahaba's Blood Demon Art grants him two morphed eyes with arrows for irises, one on each of his palms. Yahaba relies on these eyes to guide his senses and can use them to track footprints. The eyes can also conjure vector arrows when they blink, forcing the desired target in whatever direction the arrow is pointing.
- Yahaba was ranked in 37th place as of the first character popularity poll with 14 votes.