Used to belong to Hachisuka clan who ruled Tokushima domain, thus the reason of his name.
His inscription is as follow:
長曽弥興里入道虎徹 (Nagasone Okisato nyuudou Kotetsu).
寛文五年乙巳霜月十一日 弐ツ胴截断 山野加右衛門永久 (Kanbun 5 (1665 CE) Kinotomi Shimotsuki (November) 11, futatsu dousetsudan, Yamanokaemon Nagahisa) ― written with gold inlay, with a signature at the end.
Futatsu dousetsudan refers to the fact that when Hachisuka was used in a cutting test, he was able to cut down two corpses piled together. Yamanokaemon Nagahisa is the place where the cutting test was held at.
The reason he's portrayed wearing golden armors is because his koshirae color is golden-colored.