A samurai of Higo Domain who became notorious as an assassin of the pro-emperor expulsion movement in Bakumatsu Kyoto. In 1864, he boldly assassinated Sakuma Shozan—a prominent advocate of opening Japan—in broad daylight on Sanjo Kiyamachi street in Kyoto. Despite his small stature, he possessed lightning-fast swordsmanship, earning the fearsome name "Gensai the Assassin." After the Meiji Restoration he continued opposing the new government's policy of opening Japan, and was beheaded in 1871 on suspicion of rebellion, aged 37. In later generations he is considered one of the inspirations for Himura Kenshin, the protagonist of the manga and anime series "Rurouni Kenshin."

Behind a small and quiet exterior lay a lethal assassin with lightning-fast sword technique. Fiercely loyal to his convictions with no capacity for compromise, he remained a stubborn idealist opposing the open-door policy even after the Restoration.

Regarded as a model for the protagonist of "Rurouni Kenshin," he is one of the most famous Bakumatsu swordsmen in modern Japanese pop culture. His life staked on loyalist ideals symbolizes the turbulence of the Bakumatsu era.