Sara Asano

was a human princess who fell in love with Sesshōmaru and planned to steal the Tessaiga from Inuyasha in order to win the dog demon's affections.

History
Sara was the princess and daughter of a waning general losing a war. Sesshōmaru happened upon the enemy army's camp and slaughtered them all, ignoring the injury his brother inflicted on him (This was immediately following the fight in which Inuyasha severed Sesshōmaru's arm). Sara laid her eyes upon Sesshōmaru as he annihilated their enemy with such grace and power. Struck by his graceful beauty, the princess fell in love with him. She would often play her treasured flute whenever he was around, apparently keeping him company while he recuperated. In his sleep, he cursed his half-brother's name, calling out for the Tessaiga that he so desired. Word reached Sara's father about his daughter's infatuation for the demon, and unwilling to allow her to fall in love with a demon, he waged an attack against the injured, but still capable warrior. She tried to talk him out of it but his stubbornness got the best of him as he brushed off her pleas. Sara played her flute, hoping to further persuade her father to not fight. He ignored her anyway and ordered his battalion to attack. The humans were no match for Sesshōmaru as he reflected the rifle fire with a mere flick of his light whip. Defeated, the warlord retreated in cowardice. Sesshōmaru intended to pursue, but after thinking on the stream of flute music, he relented. The warlord's fear of Sesshōmaru's retaliation drove him into insanity and he committed suicide, burning down his own castle while still inside. Soon after, Sesshōmaru left and Sara succumbed to an illness which would leave her with a few days left to live. On her deathbed, Sara remembered Sesshōmaru and desperately wished to see him one more time. A legion of demons heard her plea and enticed her with the chance to meet with him again. With nothing to lose, she allowed the demons to take over her body, giving her continued life and new demonic powers. She emerged with full strength once more, seeking only to accomplish one goal: to be one with Sesshōmaru, and she knew what he wanted and she now had the power to get it.

During the story
Sara appears to Sesshōmaru hours after her cremation in hopes that he would remember her. While he does recall the event that transpired, he does not acknowledge ever actually meeting her. Sara quickly proposes that she can get him what he wants most, hoping that it would be the only way for Sesshōmaru to reciprocate those same feelings to her. Although he does not agree, he lets her to go about her business, which she takes for a yes. She returns to the village to pose as a sacrifice named Umineko to a sea god in order to lure Inuyasha out. Miroku, being his perverted self, rushes to her aid without a second thought. Sango goes on to free Sara but both she and Miroku end up suddenly petrified in glossy stone. As Inuyasha and the rest onlook the sight, Sara claims it to be the powers of the demon at work because they had saved her. Inuyasha easily dispatches of the demon but it does not undo the damage done. At a loss, Sara plans to explain as the group head back to the village...only to find all of the villagers petrified. The only way for them to undo the curse was to head to the sea god's shrine and move the stone inside. Though Inuyasha has trouble at first, Umineko suggests moving the shrine using the Tessaiga to move it. It succeeds but as the rock turns, Shippō catches on to the ploy at hand. The shrine suddenly repels Inuyasha and begins to cave in, crushing Umineko in the process, but pulverizes in a glob of seaweed, revealing her to be nothing more than a demon puppet. As Inuyasha and his friends escape the trap, they encounter Sara as she reveals herself with Tessaiga in hand. Suddenly, Sesshōmaru makes an unexpected visit before them.

Inuyasha attacks Sesshōmaru, thinking that he had planned this. The full demon casually repels his attack. Sara attempts to move in for the kill, but much to her dismay, Sesshōmaru releases his brother and fires a thick spray of his poison mist at her. She manages to avoid it in time, but now utterly confused. Sesshōmaru stated that even though his desire for the Tessaiga hasn't wavered, he will not accept the sword if he himself does not obtain it alone, let alone having it taken away and to handed it to him by a human. The dog demon leaves the scene elsewhere. Inuyasha attempts an attack on Sara but uses her pendant to petrify him. Kagome thinks quick and fires an arrow at the jewel, shattering it and undoing the petrification inflicted on Inuyasha. The half demon continues his attack but Sara repels him and flees the scene. The demon princess later finds Sesshōmaru standing in front of the tree he rested on while he was recovering. The two reminiscence about that day they met. Suddenly, Sara's eyes glint with an evil aura. Sesshōmaru senses this and quickly catches on to the plan at hand. Sara, dumbfounded, is at a loss for words. Inuyasha suddenly appears to continue his attack but Sesshōmaru draws his sword to repel him. His younger brother clinches his injured shoulder and flings his Blades of Blood as one of the stray projectiles lops off one of Sara's arms, which is quickly replaced with a group of snake-like demons that constrict him. As Sara attempts to finish what she started, Sesshōmaru stands in the way again and vivisects her. The cut causes an entire legion of demons to suddenly spew forth from her body as it undergoes a metamorphosis into an ogre demon, revealing 'her' true form. The demons reveal that they were simply using Sara's body as a medium to carry out their plan to ultimately devour Sesshōmaru, attempting to use Sara's wish to steal the Tessaiga and draw out the powerful dog demon. Sara's spirit appears and seeks to be forgiven for her actions. Without hesitation, he attempts to cut the demon down but to no avail as the demons feed on raw hatred, which apparently empowers him. Kagome attempts to purify them with a sacred arrow but her attempt is foiled. Seeing no other way to deal with this threat, Sesshōmaru takes a risk and grabs the Tessaiga and draws out its battle form despite the seal rejecting him and uses the Wind Scar to vanquish all of the demons at once.

Sara, who is now free of the demonic influence, begins to dissolve into ash, she expresses her own genuine love to Sesshōmaru and apologizes for what she had done before finally passing away with a warm smile on her face. Though seemingly sympathetic, he approaches the remains of Sara, picks up the flute and holds it during her final moments. He then looks at her and sticks her flute into the pile, leaving away with a simple passing comment: Go play your flute in the netherworld....

Trivia

 * Sara can be considered a mirror image of Onigumo. Both were on their deathbeds, yearning for their respective infatuations, when hoards of yōkai approached and offered to grant them their wish to be with them. Both accepted and, with their first actions, set out on plans to destroy the very beings they'd sold their human bodies and souls to be with (Naraku to kill Kikyō and take the Shikon no Tama and Sara to trick and eventually absorb Sesshōmaru).
 * Her death was similar to Kagura's (both of their bodies disappeared while in the presence of Sesshōmaru). Sara expressed her love for him, while Kagura only had thoughts of him.