U1 is the main alias of Bemani music composer 浅見祐一 (Asami Yuuichi), who mainly composes under this alias for the game Dance Dance Revolution. This alias is a pun on the Japanese word for 1 (ichi), therefore making U1 pronounced exactly like Yuichi in Japanese. Some of his other aliases include U1 Jewel Style, U1-Asami, sAmi, CLUB SPICE, NPD3, Chang Ma and 2MB (when remixing songs from other Bemani artists).