S1·E240 Episode 240

SING hires SAU to carry out an investigation. They find out that GUCCI had a son who had three moles on the sole of his foot, which matches with SING’s appearance. In consideration of the KIMs’ feelings, SING decides not to reveal the truth. In the hospital, SING discovers that GUCCI has leukaemia. He announces that he will donate his bone marrow to her, which shocks everyone.