On April 21, 1701, Naganori ASANO, his lord, injured Yoshinaka KIRA in Matsu no Oroka (a long corridor called matsu [pine tree]) of the Edo-jo Castle, and Asano Takumi no Kami was ordered to commit Seppuku (suicide by disembowelment) immediately on the day and 'kaieki' sanction (sudden dismissal and deprivation of position, privileges and properties) was ordered to the Ako domain.
元禄14年（1701年）3月14日、江戸城松之大廊下で主君浅野長矩が吉良義央へ刃傷におよび、浅野内匠頭は即日切腹、赤穂藩は改易となった。