Muroga Hyoma is a member of the Kouga Manjidani clan and serves as the second-in-command to Danjo Kouga, the clan’s elder leader. He is one of the ten ninjas chosen to represent Kouga in the conflict against the Iga clan. Hyoma is the maternal uncle and teacher of Gennosuke Kouga, having trained him in combat and the use of their shared hereditary technique since Gennosuke was a small child. He is also a close friend of Saemon Kisaragi, another Kouga ninja.

Hyoma is blind, but his lack of sight is no weakness. His hearing is extraordinarily acute, allowing him to detect the exact number of enemies approaching from miles away and to track opponents through sound alone. He possesses a technique known as Doujutsu, which enables him to reverse the killing intent of anyone who meets his gaze, causing them to take their own life rather than harm him. Unlike Gennosuke, Hyoma’s Doujutsu is always active, so he must keep his eyes closed at all times to avoid accidentally triggering it on allies or innocent people. He can only safely open his eyes and use his power at night. Hyoma is also a skilled swordsman and relies on his heightened other senses to fight effectively in close combat.

Hyoma is wise, honorable, and calm in demeanor. He is among the more level-headed members of the Kouga clan and is opposed to the pointless bloodshed between the two ninja families. Through his teachings, he helped Gennosuke look beyond the centuries-old hatred and pursue the possibility of peace, a goal Hyoma supports wholeheartedly. He believes in Gennosuke’s leadership and is willing to defend him with his own life. Despite his formidable power, he is not aggressive or cruel; he understands that all people, regardless of clan, live, feel, and die the same way.

In the story, Hyoma serves as a mentor and moral anchor for Gennosuke, as well as a practical battlefield asset for the Kouga. He fights to protect his clan and to uphold the truce he hopes will end the conflict. His role as second-in-command places him in positions of tactical importance, and he is respected by his comrades for his skill and judgment. His friendship with Saemon Kisaragi adds a personal dimension, as the two share a mutual trust and camaraderie.

Hyoma’s development is marked by his unwavering support for Gennosuke and his attempts to steer the clan away from blind violence. His death comes in a duel against the Iga ninja Koshiro. Because Koshiro is also blind, Hyoma cannot use his Doujutsu on him. Koshiro slashes Hyoma’s ear, destroying his ability to locate his opponent through hearing. Though fatally wounded, Hyoma remains standing after death, a testament to his endurance and will. He is the seventh of the Kouga’s ten chosen ninjas to die.