Shiori

is a half-demon born from a human mother and a bat demon father.

History
Shiori’s father, Tsukuyomaru, came from a bat-demon clan that preyed on the blood of humans and animals; Shiori’s mother’s village was one of their hunting grounds. However, Tsukuyomaru was different than the others – he did not kill humans, eventually meeting Shizu and falling in love with her. After Shiori was born, the attacks ceased and the village was at peace until the untimely death of Tsukuyomaru.

In attempts to stop the attacks on the village, Shizu, Shiori’s mother agreed to offer Shiori to her grandfather, Taigokumaru. Shiori at first refuses to leave as she was afraid of him but by the persuasion of the villagers she left hesitantly to Taigokumaru’s side.

Like Inuyasha, Shiori was bullied constantly throughout her childhood for being a half-demon despite the obvious peace that Tsukuyomaru had brought to Shiori's village. Her mother too was discriminated against and they both lived secluded from the rest of the village which showed how ungrateful the villagers had showed for the kindness that Tsukuyomaru had showed to them. When Taigokumaru broke his promise, the villagers attacked Shiori’s mother only to be stopped by Inuyasha and his friends.

During the story
Inuyasha and his group came upon Shiori as they faced the problem of Naraku’s barrier. They learned from Myōga that the Tessaiga would be able to shatter barriers if he killed the current guardian of the barrier from the bat demon clan. Inuyasha refused to kill a young half-demon, let alone a little girl, and had to find another way. In gratitude of Inuyasha reuniting her with her mother, Shiori offers to let Inuyasha destroy the red orb with Tessaiga, which allows him to gain the Red Tessaiga.

Powers & Abilities
High Demonic Power: Despite being a half-demon, Shiori is shown to have high amount of demonic powers and potential as a child of a Daiyokai. This is shown in the fact that her barriers created as the guardian of the Demon Bat Barrier are very strong and was capable of blocking nearly all attacks coming at it including the likes of the Backlash Wave. In fact when that occurred, her grandfather was very shocked at the strength of her barrier and before then was desperate to have her as the new guardian.

Weapons
Blood coral crystal (former): This crystal orb is an heirloom of the demon bat clan and is the source of their accumulated power.
 * Impenetrable Barrier: Shiori, like her father and grandfather, has the ability to create barriers from a red orb, called the Blood Coral Crystal. This skill and duty is passed down from generation to generation as the ability to create barriers wanes with age and the ability is lost once the duty has been passed to someone else. The barriers created by the bat demons are impenetrable and even deflected Tessaiga’s Kaze no Kizu and withstood the Bakuryūha.
 * Demonic Aura: The crystal can emit a powerful demonic aura that entrances half-demons like Shiori and possibly weaker demons along with burning humans if they touch it.

Relationships
Shiori admired her father greatly and was angered to the point of rejecting her grandfather from the barrier once she heard that Taigokumaru killed her father. When Taigokumaru came back one last time from the red orb, Tsukuyomaru’s soul protected Shiori and her mother from his attack.
 * Tsukuyomaru

Shiori spent most of her childhood living with her mother and would do anything for her, even if it meant separating from her to protect the village, or to protect her grandfather with the barrier in order to spare her life.
 * Shizu

Shiori was afraid of Taigokumaru and was very passive around him. When he was leading the attack on the village, he manipulated and threatened Shiori into protecting him with her barrier or else her mother would die. However, upon hearing that Taigokumaru killed her father she rejected him from the barrier, thus leaving him defenseless, and Inuyasha was able to defeat him.
 * Taigokumaru

As the two of them were both half-demons, Inuyasha was able to relate to Shiori easily by the discrimination she faced. In fact Inuyasha also had a human mother who was his only human family. In gratitude for saving and reuniting her with her mother, she helps Inuyasha make Tessaiga stronger.
 * Inuyasha

Trivia

 * Shiori is the only half-demon child in the series and manga to be shown having red lips. It is unknown if Shiori's lips are naturally red, or if she applies some substance to make them appear this way.
 * It's quite possible that Shiori might have bat-like abilities and features due to her demon heritage.
 * Because she is a half-demon Shiori probably turns human once every month. But it is unclear when she does or how much her appearance changes.
 * Shiori's ears are covered by her hair, so you never see what style they are except in a flashback of her as a baby when they are shown to be normal human shaped ears. It is unknown if this is because of it being the time every month when she turns human.