The posts referring to political hari-kari and the Emperor's honor remind me of Mishima, one of Japan's most celebrated writers at the time of this incident:
On November 25, 1970, Mishima and four members of the Tatenokai (Mishima's "Shield Society" of young martial artists loyal to him) under a pretext visited the commandant of the Ichigaya Camp - the Tokyo headquarters of the Eastern Command of Japan's Self-Defense Forces. Once inside, they proceeded to barricade the office and tied the commandant to his chair. With a prepared manifesto and banner listing their demands, Mishima stepped onto the balcony to address the gathered soldiers below. His speech was intended to inspire them to stage a coup d'etat and restore the Emperor to his rightful place. He succeeded only in irritating them and was mocked and jeered. As he was unable to make himself heard, he finished his planned speech after only a few minutes. He stepped back into the commandant's office and committed seppuku. The customary kaishakunin duty (the "Second's" duty: after seppuku the Second decapitates the suicide, so he won't suffer too greatly from the pain of self inflicted disembowelment) at the end of this ritual had been assigned to Tatenokai member Masakatsu Morita. But Morita, who was rumored to have been Mishima's lover, was unable to perform this task properly: after several failed attempts, he allowed another Tatenokai member, Hiroyasu Koga, to finish the job. Morita then attempted seppuku and was also beheaded by Koga.