The liver and gallbladder are closely related and take care of each other. Metaphor is frank communication with each other. From Song Hu Taichu's Introduction to Liao Cai in the Sun Curtain: "From now on, it is necessary to postpone seeing Liao Cai and tell its disadvantages so that you can meet each other sincerely." Biography of Heroes of Children 16: "When I watched it, we were congenial and sincere."