Bokusenō

was a wise tree yōkai and ally of the Inu no Taishō who would use the wood from Bokusenō's own boughs to craft the scabbards for two powerful swords, the Tessaiga and the Tenseiga. Bokusenō was familiar with the Inu no Taishō's designs and was the only one of his allies and vassals who got along with the Inu no Taishō's eldest son, Sesshōmaru. As such, Bokusenō is instrumental in developing Sesshōmaru's understanding of Inuyasha's hanyō nature and the connection between Inuyasha and the Tessaiga. Bokusenō was also the means by which the Tenseiga was delivered to Sesshōmaru, since the Inu no Taishō's vassals were too afraid of Sesshōmaru to deliver it themselves. Because of the information Bokusenō gives Sesshōmaru on Inuyasha's demon blood, Sesshōmaru ultimately gives up on his quest to claim the Tessaiga and allows his younger half-brother to maintain possession of the sword.

History
Bokusenō was originally a simple, but as he grew older he eventually gained additional powers and transformed into a yōkai, similar to how kitsune and bakeneko start out as ordinary foxes and cats, respectively. Because of his great powers and wisdom that have accumulated throughout his 2,000 years of life, Bokusenō became an important ally for the Inu no Taishō, a powerful dog daiyōkai who had two swords of great power crafted from his own fangs, the the Tessaiga and the Tenseiga. In order to contain their extraordinary powers, the Inu no Taishō sought out Bokusenō to beseech him for the use of the wood from his very own boughs to use as sheathes. Since the two swords possessed such awesome powers, no ordinary would could suffice. Bokusenō consented, and the craftsman Tōtōsai created two sword sheathes for the Dog General's swords. These sheathes had strange powers of their own, as would anything crafted from the wood of such a powerful tree, and would prove invaluable to their users over the years. It is unclear what relationship Bokusenō had with the Inu no Taishō beyond the provision of his wood for the sword sheathes, but as Bokusenō would later reveal, he had intimate knowledge of demon lore and of the Inu no Taishō's sons in particular, despite his sedentary nature. Whether this is because he was close in the Dog General's counsels or was simply capable of discerning such things through his own wisdom is unclear.

His face emerges from the surface of his trunk and he can grow arms from his trunk at will.

The Tenseiga is delivered to Sesshōmaru by Tōtōsai, who hangs the sword on Bokusenō with an attached note. Being used in this way causes Bokusenō some minor discomfort.

Sesshōmaru came to see him on Inuyasha's scent changing to of a full demon twice (when Naraku's third incarnation, Goshinki, broke the Tessaiga, and when Inuyasha lets go of the Tessaiga during a battle with Sessōmaru himself). Bokusenō tells Sesshōmaru that Inuyasha can never be a full fledged demon and explains that when Sesshōmaru is in battle, he remains calm, and doesn't lose control. When Inuyasha's life is on the line, however, his demon blood awakens his most basic survial instincts. As his demon instincts take over, Inuyasha's human soul becomes overpowered by his demon blood, and he turns into a ruthless beast. As Bokusenō said, "In further transformations, he would loose part of his human soul. He would not tell the difference between friend or foe. He would only know how to kill until he is destroyed." Sesshomaru understands why Inuyasha has the Tessaiga, and he goes to find Inuyasha to see if Bokuseno's words are true.

Bokuseno Bokuseno 朴仙翁