The principal amount (borrowing amount) written on the pledge bill was equivalent to the servant's value and the interest of the debt was equivalent to servant's labor during the debt period, and the servant was bounded by his master i.e. creditor until he as debtor wiped off the principle amount, but in fact it was fudai genin by de facto human trafficking under the name of pledge.
これは質券に書かれた本金（借入額）を奉公人の価格・利息の支払を債務期間中の労働に相当させ、借方である奉公人が本金を返済しない限りは身柄は修身にわたって貸方である主家に拘束されるという仕組であり、質取行為に名を借りた事実上の人身売買による譜代下人であった。