Episode 15: Farewell Under the Lunar Eclipse
Instead of a full summary, let's recap what we learned in this episode:
First of all, the story is told by Riku. Riku is referred to as "Pirate washed Ashore", but anyone who's been watching knows there is much more to him than that.
Eighteen years ago (one month after Root Head was defeated), the Purveyor of Jewels, Hosenki II, created the black pearl using a rainbow pearl leant to him by Riku and Lady Izayoi's (InuYasha's mother) rouge.
The black pearl is the jewel that leads to the border of this World and the afterlife. Hosenki II gives the pearl and the rouge to InuYasha, who places the pearl within his eye.
Four years later, Rin gives birth to Sesshomaru's daughters, Towa and Setsuna.
Kirinmaru's older sister, Zero, approached Sesshomaru just before their birth threatening their lives on behalf of her brother. However, she seems to hate half demons more than him.
The Shikon Jewel had predicted that it was neither a human being nor a youkai who would defeat Kirinmaru.
Sesshomaru takes the twins and hides them within a barrier created by Jaken.
Beforehand, Lady Joka had attacked Sesshomaru, but he cut off her arms and confiscated the gold and silver rainbow pearls. He put one in each of his daughters' eyes.
Not long after sealing his daughters, Sesshomaru visits Kirinmaru. He agrees to help destroy InuYasha and family.
With all their lives in danger, Kagome entrusted Moroha to Hachi, who took the child to Koga's wolf clan.
Instead of killing InuYasha, Sesshomaru extracts the black pearl from InuYasha's eye and seals away both Kagome and InuYasha.
NOTE: Hisui was an infant when the story began making him 17 going on 18 years of age. Also, the Grim Comet event may of been a means to show that InuYasha was still needed.