Haohmaru/Story

Past
At the age of fifteen, he challenged Jubei Yagyu to a duel but lost due to lack of experience. Jubei, amused by the youth's bravado, brought Haohmaru to Nicotine Caffeine so that he may gain proper training. Whilst living there, he also met and befriended Genjuro Kibagami, fellow student and another orphan like himself.

Both students were close friends, yet Genjuro's hunger for power worried Nicotine. To test his students, he tempted them to fight over the treasured sword, Fugudoku. They were tested by facing off with a group of other fighters. In contrast to his friend, Haohmaru fought only until his opponent lost the will to fight and didn't give chase. After Genjuro left Nicotine's home, Haohmaru was rewarded with the sword. Encouraged by his master to further improve himself, Haohmaru travels the lands perfecting his sword skills, and searches for worthy challengers in the name of Shura.

Samurai Shodown V
Haohmaru challenges Yoshitora to a duel in order to test his own strength. In his ending Yoshitora accepts his challenge, asking the latter to join him and help him build a new country. Haohmaru replies that if he loses, he'll join Yoshitora. They fight but the result of their match is uncertain. 2 years later after confronting the unusual anomalies brought about by Shizuka Gozen, Haohmaru embarks on a journey to stop Amakusa from bringing Ambrosia into the mortal realm. After killing Amakusa, Oshizu appears to him, having followed him to Shimabara. He dismisses her, telling her that he can't choose between his sword and his woman and leaves.

Samurai Shodown III & IV
Not long after, he encounters Shizumaru Hisame and teaches him the philosophy of the sword at an early age. A woman named Shiori meets the wandering Haohmaru and asks him to kill the "demon". Thanks to Haohmaru's teachings, Shizumaru slays Zankuro and avenges his parents death in the process. Haohmaru continues his journey shortly after and runs into Genjuro in Samurai Shodown IV, the outcome of their duel is unknown.

Samurai Shodown I & II


One night, Haohmaru was suddenly attacked but easily defeated the sinister assailant. Haohmaru's attacker who was being manipulated by an evil force told him that his soul will be used for Ambrosia's resurrection. Haohmaru, sensing an evil force rivaling Amakusa, pays a visit on his old fencing master. While Haohmaru relates his story, his master's visage grows unusually grim. He tells Haohmaru to stay away, he acknowledges how much stronger Haohmaru has gotten but forbid him from confronting the threat head on. The two share a few drinks to celebrate their reunion after a long separation, at dawn Haohmaru slips out unannounced to embark on his next journey. At the end of Samurai Shodown II, Haohmaru defeats Mizuki and leaves the Makai gate that Nakoruru seals shortly after. In his ending, Genjuro approaches a wounded Haohmaru with the intention of killing him, Oshizu however runs to the wounded Haohmaru's side. She pleads Genjuro to not kill him, and instead challenge Haohmaru when he's better, this results in Genjuro sparring his life. Haohmaru embraces Oshizu and then apologizes to her, as he still wants to dedicate himself to his swordplay.

Samurai Shodown 64
Haohmaru continues to travel the land to polish his fighting skills. However he notices a mysterious woman has been persistently tailing him. Haohmaru has no idea who she is, but he is soon reluctantly caught in the designs of the evil, dark figure who manipulates her. It's later revealed that the mysterious puppeteer called Yuga the Destroyer, is seeking a male counterpart to Shiki and chooses Haohmaru to fulfill its requirements for a perfect resurrection. The two face each other and Haohmaru emerges victorious destroying Yuga's physical form in the process. A year later, a brainwashed Shiki and Shadow Asura ambush Haohmaru and turn him into a cold blooded murderer also known as “Sword Demon Haohmaru”. Together with Shadow Asura and Shiki, they defended the entrance of Yuga’s lair.

After the two Asura's killed Yuga, Shiki along with Haohmaru were finally freed from Yuga’s influence and returned to their normal states. In Genjuro's ending, he and Haohmaru face each other once more, but this time Genjuro gains the upper hand. Before he could deal the final blow, a boy stabs him in vengeance for his unnamed father. It's heavily implied that Genjuro dies from his wound and, as promised, an older Haohmaru toasts to his friend's honor. Shiki leaves her daughter under Haohmaru and Nicotine's care as her servitude to Yuga made her feel unworthy of being a mother.

Samurai Shodown: Warriors Rage
Haohmaru is a skilled and active swordsman at the age of forty-seven who is revered by many to be the "Legendary Swordsman". He learns that his adopted niece, Mikoto, ran away from the temple (her childhood home) and follows her to the cursed island of Riten Kyo. There, he grows aware of the evil entities at work there, and departs on a journey to stop the Razor Trio, as well as duel worthy opponents along the way. Haohmaru was also informed of a "catastrophe" that may occur on the cursed island by the holy spirit Nakoruru. He kills Oboro and in his ending, Haohmaru eventually reaches Mikoto at Riten Kyo and reveals her unspoken past to her.

Samurai Shodown Sen
Haohmaru inspires Takechiyo. Like with Shizumaru he would guide him and challenge him to a duel after a certain amount of time to test his skill and resolve.