Otoya Yamaguchi was an ultranationalist and a member of the right wing Uyoko dantai group. He assassinated the head of the Japanese Socialist Party, Inejiro Asanuma, during a televised live debate in advance of parliamentary elections. Millions of people were watching at the time.
Less than three weeks after the assassination, while being held in a juvenile detention facility, Yamaguchi mixed a small amount of toothpaste with water and wrote on his cell wall, "Seven lives for my country. Long live His Imperial Majesty, the Emperor!" Yamaguchi then knotted strips of his bedsheet into a makeshift rope and used it to hang himself from a light fixture.[3] The phrase "seven lives for my country" was a reference to the last words of 14th century samurai Kusunoki Masashige.
https://en.m.wikipedia.org/wiki/Otoya_Yamaguchi