Sesshōmaru was a powerful dog daiyōkai and feared throughout the feudal world. He was the half-brother of the hanyō Inuyasha and the first son to the Inu no Taishō, their father. Unlike many other yōkai, he had no interest in possessing even one shard of the Shikon no Tama to enhance his powers. On his journey, he was accompanied by a two-headed dragon named A–Un, a demon imp named Jaken, and an orphaned human girl named Rin.
Sesshōmaru, dissatisfied with his sword Tenseiga, wishes to have the old, absent-minded sword smith Tōtōsai make him a new one. The unwilling Tōtōsai has Inuyasha defend him, causing the brothers to fight. Tōtōsai reveals the heritage of Sesshōmaru’s sword before creating a diversion to allow Inuyasha and the rest of his companions to escape. Soon after leaving Inuyasha and his companions, Tōtōsai is attacked by Sesshōmaru. Once again, Inuyasha battles his brother as Tōtōsai’s protector, but must now face Sesshōmaru’s newest defense: a dragon’s arm. As Inuyasha and Sesshōmaru continue to duel for possession of Tessaiga, both brothers discover the unexpected power of their respective inheritances, as Inuyasha discovers the true power of his sword, and Sesshōmaru, who called his sword useless, is saved by his father’s heirloom. After the fight, an injured Sesshōmaru is helped by the orphan Rin, whom he was originally going to leave dead but revives with the Tenseiga after she is killed by Kōga’s wolves because it pulsed. He then sets off and Rin follows him, becoming his companion.
The same cosplay costume comes from: http://www.eshopcos.com/inuyasha-sesshomaru-kimono-cosplay-costume