The Abe family has had extraordinary powers for generations. In order to use this power to help people in need, they opened Yin Yangliao, a firm that specializes in handling special commissions. As the members of the 25th generation Onmyoria, headed by Abe Seimei, continued to deal with various commissions, they gradually discovered that the mastermind behind all incidents pointed to a frail young man. Moreover, this boy's life experience is actually related to the secret behind the Abe family...