In 1842, when Yukitsura SANADA, the lord of Matsushiro Domain, whom Shozan served, was appointed Kaibo gakari (coastal defense) concurrently with Roju (member of shogun's council of elders), circumstances turned 180 degrees for Shozan.
ところが天保13年（1842年）、象山が仕える松代藩主真田幸貫が老中兼任で海防掛に任ぜられて以降、状況が一変する。