Episode 21 (Hanyō no Yashahime)

"Secret of the Rainbow Pearls" is the twenty-first episode of Hanyō no Yashahime.

Summary
Kaede tells Towa the story about how their young teenage human mother, Rin, had mysteriously disappeared after giving birth to them fourteen years prior. While reflecting, Towa, who has been affected by the new moon again, is approached by Riku. He tells her the story of the demon female who had looked after him many, many years ago and how the seven Rainbow Pearls were created after her grandfather Tōga's demise a couple centuries ago. Riku finally puts his plan into action by luring Towa into a trap. Distracted, a defenseless Towa is attacked by Tōtetsu, which Riku does not take kindly.

Plot
223 years ago, amidst the news of Tōga's impending demise after his epic battle with Ryūkotsusei, two of the Four Perils, Konton and Kyūki, urge their master, Lord Kirinmaru, to seize the opportunity to attack his rival when he is on the verge of death. Lord Kirinmaru angrily refuses however, seeing attacking his rival when he is weak as cowardly and dishonorable. He then orders his most loyal retainer, Riku, to deliver medical herbs to wounded Lord of the Western Lands. Unfortunately, Riku arrives to find the estate of Lady Izayoi burning and the great demon dead after a final battle with Takemaru of Setsuna. Upon hearing this, a saddened Zero, who held romantic feelings for Tōga, decides to use the Shikon Jewel to seal her emotions, which creates the seven Rainbow Pearls.

Back to the present, its the new moon and with Towa's power diminished, Setsuna orders her to take shelter at Kaede's home. In the occasion, Kaede reveals to Towa that she lived many years with Rin until her disappearance that occurred just after she gave birth to the twins. Seeing a Dream Butterfly passing nearby, Towa chases after it all the way to the Sacred Tree of Ages, until she saw the fireflies and follows them to spot where she meets Riku. To Towa’s surprise, Riku makes flirtatious compliments towards her in her human form, remarking her it as “exceptionally beautiful” and noticing the sparkles in her eyes, all the while gently caressing her extended hair with his fingers.

Soon after, Towa and Riku sit together on a nearby log, where Riku uses his earring to heat some modern tea that Towa has brought with her. After having some tea together, Riku and Towa stare at the winter fireflies together, where Riku reveals that they, like humans, have short life spans that could burn up at any moment; the reason he finds both so beautiful. The two then begin to stare up at the sky together, where Riku discusses his master, whom he does not reveal to be Lord Kirinmaru, revealing that he holds a certain amount of reverence for the the stars and sky. Riku then discusses how he is distancing himself from his master because they both desire the same thing: the rainbow pearls. Riku reveals that he intends to gather all Rainbow Pearls and return Zero's lost emotions to her. To do this however, he will need to take Towa’s as well and then proceeds to, painlessly, remove it from a defensive Towa’s eye. Before he can take it though, Tōtetsu appears to attack Towa, knowing from Konton that she loses her powers in nights with new moon light. Though both he an Tōtetsu serve Lord Kirinmaru, Riku risks his life to defend Towa from the gluttonous demon, angrily seeking revenge upon him for ruining their “date”. During the clash, Riku is injured when he uses his body as a shield to protect Towa from miasma-poisoned insects launched back at them by Tōtetsu. Helping the injured Riku to his feet, Towa and he run off into the forest. While inside, Riku reveals himself to be a vassal for Lord Kirinmaru, causing Towa why he would risk his life to defend her. Though he is confused as to his actions himself, Riku makes an incomplete confession of his feelings towards Towa, leaving her shocked and blushing.

So after however, Tōtetsu finds them again and begins their attack. While Riku attempts to distract Tōtetsu by sacrificing himself so that Towa can escape, Setsuna and Moroha arrive to help them. Soon after Towa’s powers are restored by the rising sun, Riku takes the opportunity to slay Tōtetsu and take the Rainbow Pearl that was in his possession. Riku then teleports over to the princesses’s position, where he, relieved in her safety, gives the blushing and flustered Towa a hug. Before Riku leaves, Towa, grateful to him for saving his life and touched by his feelings towards her, gives the Rainbow Pearl in her possession to him to help with his mission. Riku takes it with the hope that they will meet again soon. Towa soon regrets her decision however, when Setsuna points out that Riku's master could use them for evil ends causing her to scream into the woods for Riku to give it back. Riku then wanders through the forest smiling over both acquiring two more of the Rainbow Pearls, along with his growing feelings for the half-demon princess.

Trivia

 * Towa confirms that it's currently winter. Though unlike winter in the modern era, the weather is only mildly cold as Towa doesn't feel cold in her human form until a breeze strikes.
 * This marks the second time Towa becomes full human.
 * Towa learns from Kaede that her mother's name is Rin.
 * Towa, Setsuna, and Moroha discover that Riku seeks to collect all the Rainbow Pearls, including their’s.
 * Tōtetsu being weakened by miasma bees of the dead summoned by Riku while using his air breath is similar to Miroku being weakened by the Saimyōshō of Hell while using his Wind Tunnel.
 * As of this episode, all the Four Perils have been slain.
 * Towa gives her Rainbow Pearl to Riku.
 * This is the first time that the Sacred Jewel is shown via through a flashback around the time that Inuyasha was born, as well as Tōga's death.
 * Tōkotsu is the only Shikyō to not appear in this episode at all.
 * It's been revealed that Riku is only a doll since he was around the era of the Great Dog General's reign.
 * Kaede confirms Rin disappeared shortly after giving birth to the twins.

Error

 * Tōga is said to have sustained grave injuries from battling Shishinki and Ryūkotsusei, although Tōga had fought Shishinki and stolen his technique before he and Kirinmaru destroyed the Grim Comet 500 years ago as he was using an incomplete Meidō Zangetsuha. Unless Tōga fought Shishinki again.