Officers called doshin were placed under shomotsu-bugyo, in the salaries based on their social statuses, and the number of these officers was four in 1694 and was increased later to 21in the later Edo period.
書物奉行の配下に同心がおり、持高勤めで、元禄6年（1694年）に4人、以降増員され江戸後期には21人いた。