Inaho Hitomebore is a wealthy, self-indulgent teenager living in 1920s London, consumed by the desire for eternal youth and everlasting beauty. This singular ambition drives her to seek out the ancient vampire Alucard von Mosquiton and revive him using her own blood. The act creates a binding "blood contract," placing Alucard under her control as a slave or subordinate whose supernatural powers she leverages for her goals.

Her quest focuses on acquiring the legendary O-Parts, artifacts rumored to bestow immortality without the drawbacks of vampirism. She covets them not only for eternal youth but also as valuable commodities for potential resale, reflecting her materialistic nature and desire for wealth. Selfish, impulsive, and domineering, she consistently disregards the consequences of her actions on others.

Although Alucard harbors romantic feelings towards her after she saves his life, Inaho maintains a purely transactional and dismissive relationship with him. Her grandmother's historical connection to Mosquiton influenced her decision to find him, though her motives remain entirely self-serving. Their dynamic is complicated by Alucard's violent tendencies when consuming blood, which sometimes compels her to subdue him.

Throughout her adventures, she confronts supernatural adversaries, rival O-Parts seekers, mythological creatures, and Mosquiton's former associates, including his centuries-old ex-fiancée. She avoids personal combat, relying instead on manipulating Mosquiton and his guardians. While claiming pacifism, she frequently endangers others to advance her objectives.

Inaho undergoes no significant development in official media, remaining steadfastly focused on immortality and wealth. Her vanity and capriciousness define her interactions, particularly her exploitative treatment of Mosquiton, whom she uses for protection and companionship during their travels.