Matamune (マタムネ) is a fictional character in the Shaman King manga series. Matamune is a Goryoushin created by Asakura Hao in his first life. In both the Drama CDs and in Funbari Spirits, he is voiced by Hideyuki Tanaka.
Matamune is a Nekomata, a type of cat spirit with two tails; he also carries around a kiseru with him and wears a necklace with three bear claws that would later be passed on to Asakura Yoh. He has served the Asakura family for millennia, although he spends much of his time traveling the world. He professes to have seen everything and is almost constantly reading books. He also appears philosophical. To this day he still holds regrets for not being able to help his master, Asakura Hao.
A thousand years ago, he was just a normal cat, but he was abandoned by his mother, and his eight other siblings died. He was found and taken in by Asakura Hao who sensed the cat's strong spirit. He became Hao's faithful companion and a real friend.
When Matamune died, Hao turned Matamune's spirit into a Goryoushin. Hao also imbued Matamune with a portion of his own Furyoku using the Bear's Claw Necklace. This Furyoku allowed Matamune to have a physical body, and so long as Matamune's Furyoku was not used up, his physical body would continue to exist.
Matamune would eventually side with the Asakura family to defeat Hao, who had been driven mad by his own abilities. When Hao was reborn 500 years later, Matamune teamed up with Asakura Yohken and killed Hao in the Shaman Fight. Matamune holds himself responsible for what happened to Hao, believing that his loss of faith in Hao was part of the cause of Hao's madness. As such, Matamune has spent the last thousand years searching for a way to atone, and to save Hao.
When Asakura Yoh went to meet Kyōyama Anna for the first time, his grandfather, Asakura Yohmei summoned Matamune to accompany him. Matamune and Yoh became good friends, and Matamune taught Yoh a number of things. Matamune resolved to help Yoh save Anna, who like Hao, possessed the ability to read minds and summon Onis.
The Oni turned on Anna, terrorizing and threatening to destroy her. Matamune gave his power to Yoh, who was then able to defeat the Oni which was terrorizing Anna. However, the fight used up his remaining Furyoku and meant that Matamune was unable to return to his normal form. Yoh promised Matamune that one day he would become strong enough to be able to summon him once again.
While Yoh is in Hell, he feels Matamune's soul but he later forgets it. He is seen behind a rock and he says: "He is very intuitive, like always". After this he sees the arrival of the train of the death, so he can finally move on as he sees Asakura Yohken fighting Yoh.
His final words to Yoh are that he is going to be waiting for the day that Yoh summons him with his full power. Matamune also gives instructions to the other Four Elemental Warriors of what to do to leave hell.
Later in the epilogue, he is seen by Hao's side as he happily observes the Five Elemental Warriors' reunion seven years after the Shaman Fight.
Oversouls and Techniques
O.S. Oni Goroshi
O.S. "Oni-Goroshi" (O.S.鬼殺し) 
- Shaman: Matamune; Asakura Yoh; Asakura Yohken
- O.S. Type: Weapon Type
- Spirit Ally: Matamune (Nekomata spirit)
- Medium used: Kiseru (Matamune) / Bear-talon necklace (Yoh) / Shakujo (Yohken)
Description: This sword-shaped OS in the form of Matamune's soul in O.S. mode. Using the Chō Senji Ryakketsu - Fumon Tonkou supplementary, he can extend the flow of his Furyoku into his Kiseru and transform a portion of his spirit into a gigantic katana magically-imbued to ward off evil spirits. At the age of 10, Yoh reluctantly wielded this OS at the behest of Matamune, even though both knew doing so would deplete the remainder of Matamune's Furyoku in the process. Yoh materialized the Oni-Goroshi OS through his trademark bear-talon necklace, which originally belonged to Matamune that was his anchor to the physical plane. This was also the OS that Yoh's ancestor Yohken wielded, using a Shakujo as a medium.
- Kokusatsu (剋殺, Victory Killer): An attacking technique Matamune uses with his OverSoul. Matamune can increase the strength of the attack by pouring more of his Furyoku into it.
Matamune didn't appear in the 2001 Anime Series, so it's never explained who exactly defeated Patch Hao, nor is it explained how Yoh got the bear claw necklace.
- Yoh continues to wear the bear claw necklace because, when he is strong enough, he wants to use it to return Matamune to his physical form.
- Shaman King Manga - Chapter 169, Pages 7-13
- "Oni-Goroshi" (鬼殺し) means "Ogre Slayer" in Japanese
- Bakeneko - A Wikipedia article about the type of spirit on which Matamune is based