YKWTD is a maimai original track by Japanese producer r-906, featuring the vocal synthesis of Hatsune Miku (初音ミク). The title is an acronym for "You Know What To Do," a phrase that repeats throughout the lyrics as an insistent, almost chant-like hook. Released in the maimai DX PRiSM update on September 12, 2024, the song was initially gated behind a distance-based unlock in Sky Street Area 6 (スカイストリートちほー6), requiring players to accumulate 300 km of cumulative play before it became playable, a requirement later removed in the subsequent CiRCLE version. Musically, YKWTD drives forward at 174 BPM on a foundation of r-906's own slap bass, layered with crisp electronic percussion and Hatsune Miku's processed vocals weaving between English commands ("TURN THE BEAT ON / TURN THE BASS UP / YOU JUST TRUST ME") and Japanese verses. The lyrics touch on themes of inferiority and self-assertion, with imagery of moonlight spilling through holes in an umbrella. The accompanying video was created by 安倉 and K島, with jacket art by illustrator fzwrAym. In-game, the song carries a brief flavor text set in a mythological register: "Long ago, in a land called Yama, twins were born. The elder brother possessed the wisdom to forge metal, while the younger had the power to speak with the gods. It was the mark of inheriting the 'blood' to lead the clan." The connection between this framing and the song's title or lyrics is left implicit, inviting interpretation. The two upper DX charts were assigned to different note designers, 鳩ホルダー (Hato holder) for Expert at level 11, and カマボコ君 (Kamaboko-kun) for Master at level 13+ (constant 13.8), with the Master chart demanding 845 total notes across all five note types, featuring an unusually dense concentration of Slide and Touch patterns.