In 1848, he became buke tenso (liaison officers between the imperial court and the military government), and frequently went down again to Edo to negotiate with the Edo bakufu (Japanese feudal government headed by a shogun) on the policy toward the United States.
1848年（嘉永元年）には武家伝奏となり、たびたび江戸に下って対米政策について江戸幕府と交渉した。