D-51 (ディー・ゴー・イチ Dī Gō Ichi) is a Japanese popular music group consisting of two men, YU and YASU. They are signed under Pony Canyon label. According to its members, the name D-51 came from JNR's steam locomotive D51 class. In 2005 they had their first big hit with the single NO MORE CRY, which peaked at no. 5 on Oricon charts and became the 13th best selling single of the year, selling 402,034 copies.