Balalaika ("Fry Face" or "El Capitan" - called by her subordinates) is the boss of the Russian crime syndicate 'Hotel Moscow', a branch of the Russian mafia based on Thai soil. Before joining the mafia, she was a VDV paratrooper and officer in the Soviet army during the Soviet war in Afghanistan. Obviously she served as a sniper; 'balalaika' is a nickname for SVD (Dragunov Sniper Rifle) in Russian Army.

The male protagonist, a hybrid of a youkai-dog and a human, a half-demon ("han'yo" in Japanese). He wields the Tesusaiga (pronounced "Tetsaiga" in the American dub), a supernatural sword made from one of his deceased father's fangs. This sword, when properly wielded, can destroy one hundred demons with a single swing, and has further powers which are revealed as the story progresses. It is also a source of which hatred exists between Inuyasha and his brother Sesshomaru, a full youkai dog demon, being that Inuyasha can weild the Tessaiga and Sesshomaru can not. Inuyasha has a tendency for massive regeneration and can recover from injuries which would be fatal for any average human. This ability is likely derived from his youkai powers (Example: Episode 5, when Kagome brings medicine from her time). On the night of the new moon each month, Inuyasha will change into a normal human with black hair, brown eyes, and loses his yokai power during this time. Prior to meeting his current companions, he would conceal himself during this time. Inuyasha loves Kikyo, and still does, but things get complicated when he starts to develop feelings of love for Kagome. He has mastered different abilities for his sword including the red tetsusiaga that can destroy barriers and also learning the backlash wave which hurls an opponents demonic energy right back at it.

Orochimaru is a former student of the Third Hokage. Orochimaru and his former teammates, Jiraiya and Tsunade, are known as the "Legendary Three Ninja" or simply the "Sannin".

Grimmjow appears to be a laid back and irreverent individual, but this scruffy appearance hides an impulsive, excessively violent personality and a lethally short temper. Grimmjow is blunt, rude, and quite sadistic, revealing an insane grin in battle, much like Kenpachi Zaraki. Grimmjow has little respect for authority and says whatever is on his mind, regardless of whether or not it is appropriate. This attitude leads to conflicts with Kaname Tōsen, who holds Grimmjow in the same low regard as he did Zaraki. He also has conflicts with Ulquiorra Schiffer, the 4th Espada, usually because Ulquiorra interrupts his fights or doesn't act on his own impulses. He has also developed a grudge against Ichigo Kurosaki for wounding him during their second fight, and is eager to return the favor. He purposefully kept the large scar on his chest from their first battle as a reminder of this.