 They broke into Kira's mansion in Edo, captured and executed Kira, and laid his head at the grave of Asano at Sengaku-ji.They then turned themselves in to the authorities, and were sentenced to commit "seppuku", which they all did on the same day that year.Ōishi is the protagonist in most retellings of the fictionalized form of what became known as the Akō incident, or, in its fictionalized form, the Treasury of Loyal Retainers ("Chūshingura").