Myoga is a male flea yōkai who originally served Inuyasha’s father, the great dog demon Tōga, as a faithful retainer. After Tōga’s death, Myoga was entrusted with guarding the hiding place of the sword Tessaiga within his former master’s grave. He remained unaware of the grave’s true location for many years, only rediscovering it when Sesshōmaru began searching for the weapon. Following that confrontation, Myoga sought out Inuyasha and began acting as his servant, offering insight on enemies, current events, and the shards of the Shikon Jewel.

Myoga is defined by a strong sense of self-preservation. He is notably cowardly and is usually the first to flee from any sign of danger, a habit the other characters use as a warning that trouble is near. Despite this, he is extremely knowledgeable about yōkai lore and ancient artifacts, and his advice is often valuable to Inuyasha’s group. He appears unpredictably, sometimes disappearing for long stretches before reappearing with useful information. His core motivation is to serve Inuyasha as a way of staying loyal to his former master’s legacy, though he also seeks to avoid harm to himself.

His primary role in the story is that of an informant and occasional healer. He is rarely involved in direct combat, and when he is, he is easily crushed by allies who mistake him for an ordinary bug. His most notable ability is sucking venom or poison from a person’s bloodstream, an act that saved Inuyasha’s life on one occasion when a spider yōkai’s poison was extracted. He also enjoys drinking yōkai blood, which often leads to him being swatted away. Myoga appears to be functionally immortal, as even when he is squashed he survives without lasting harm.

Myoga’s key relationships include his bond with Inuyasha, whom he serves despite the half-demon’s frequent irritation with him. He is good friends with the swordsmith Totosai, another old associate of Tōga, and often spends time at Totosai’s forge when he is not with Inuyasha’s group. He is also engaged to a female flea yōkai named Shoga, but he repeatedly runs away from her to avoid the marriage. His relationship with Sesshōmaru is distant; Myoga fears the older brother and fled when Sesshōmaru came for Tessaiga. Throughout the series, Myoga’s personality and behavior remain largely static. He does not undergo major development, continuing to be a cowardly yet reliable source of knowledge. In the series finale, he chooses to permanently reside with Totosai. He also reappears in the sequel series Yashahime: Princess Half-Demon, still serving in a similar advisory capacity.