Rainbow Pearls

The were seven powerful multicolored pearl-sized artifacts with immense Yōki.

Description
These pearls appear to be in multiple colors, hence why they are referred as "Rainbow pearls". There were at least five pearls confirmed to exist in episode 7:


 * (inside the left eye of Towa);
 * (carried by Moroha, originally Tōkotsu);
 * (inside the right eye of Setsuna);
 * (on the left ear of Riku);
 * (in possession of Kyūki);
 * (on the left ear of Riku);
 * (in possession of Kyūki);

Effects



 * Opening time portal: This ability first activated when Towa's Silver Rainbow Pearl transported her to the modern era when she was a toddler. Years later, another portal to the modern era transported Setsuna, Moroha, and Mistress Three-Eyes. After defeating Mistress Three-Eyes, the pearls of the three heroines facilitated their return to the feudal era.
 * Amplifying demonic power: When Mistress Three-Eyes consumed the Red and Golden Rainbow Pearls, it greatly enhanced her offensive and defensive capabilities.
 * Activating the energy blade of Kikujūmonji: Using the Silver Rainbow Pearl, Towa can fully use the powers of Kikujūmonji, and form a blade of pure energy that extends from the broken sword.
 * Exorcism of demonic energy: In cases demonic possession, the Silver Rainbow Pearl allows Towa to separate the demonic entity from the victim, and grants direct attack to the demon without harming the host.

Warring States Era
Sometime in their early childhood, Towa and Setsuna each had a Rainbow Pearl - silver and golden, respectively - inserted one of their eyes. The red pearl was previously owned by Tōkotsu, and was confiscated by Moroha after she slew him.

When Towa and Setsuna were 4-years old, they were separated from each other in forest fire. While desperately searching for her younger sister, Towa's silver Rainbow Pearl opened a a time portal that forcefully sent her into present-day Japan, where she is found and raised by Sōta Higurashi, and his family.

Throughout the Series
For 10 years since the twins' separation, Towa lived in the present with the Higurashi family, and Setsuna lived in the past with the Demon slayers, respectively.

Back in the past, the Demon Slayers Hisui, Kohaku and Setsuna cornered Moroha because they mistook her for a demon that is attacking the locals. However, real culprit Mistress Three-Eyes appeared and stole the red and gold Rainbow Pearls in Moroha and Setsuna's possession.

Suddenly, a portal opens, dragging Setsuna, Moroha, and the Mistress Three-Eyes to the present before Towa, who recognizes her long-lost beloved twin sister. Sensing the silver Rainbow Pearl in Towa's possession, Mistress Three-Eyes attacks Towa. Much to Towa's surprise, her sword breaks when she tries to slash Mistress Three-Eyes, but Towa manages to use the Silver Rainbow Pearl's power to convert the broken hilt into a laser blade and damage Mistress Three-Eyes. Setsuna finishes her off with her weapon, allowing her and Moroha recover their Rainbow Pearls.

Trivia

 * The Rainbow Pearls share similarities with the Sacred Jewel:
 * They are spheric jewels
 * They can enhance demonic power
 * The Golden and Silver pearls inside the right eye of Setsuna, and left eye of Towa, respectively, mirrors Inuyasha's right eye holding the Black Pearl that opened a portal to Border of the Afterlife that led to the tomb of Tōga.