Meitantei Conan S13E02 - 小さな依頼者（後編）

A picture is found on his cellphone; The culprit is a woman with a mole near her breast. Conan finds out who the murderer is. Conan also figures out the culprit was one of the woman who pretended to be his mother and was the one to spread the rumors. Conan reveals that his real mother is also here, and that she truly loved her son and the same for her son; the postcards were dirty because they were stained with tears. While signing autographs, Kazuki gives his mother a postcard and tells her to send it to him or he'll visit her again. He leaves while wearing his sunglasses and his mother cries and apologizes to her son.