He made a plan with Soejima to advise Yoshinobu TOKUGAWA, Seii Taishogun (literally, "great general who subdues the barbarians") in the Taisei Hokan (transfer of power back to the Emperor), then fled from Saga Domain and went to Kyoto, however, he was arrested and repatriated to Saga and ordered not to leave his house for a month.
慶応3年（1867年）、副島と共に征夷大将軍徳川慶喜に大政奉還を勧めることを計画し、脱藩して京都へ赴いたが、捕縛の上、佐賀に送還され、1か月の謹慎処分を受けた。