Any spies entering its territory were severely punished, even if they were related to Bakufu, and thereby the clan endeavored to avoid the leakage of information, continued to accumulate foreign currency through secret trade with overseas countries, and acquired military power exceeding that of Bakufu.
越境してきた密偵はたとえ幕府関係者であろうと厳しく断罪し、情報の漏洩防止に努め、密貿易によって外貨を蓄え続け、幕府に勝る軍事力を獲得した。