Big Daddy is a hardcore track by USAO (Masaharu Kubota), a prolific Japanese composer and DJ known for his aggressive, high-BPM style across rhythm-game and doujin scenes. The song first appeared on the 2019 compilation album ANTHEM COLOR, Club Music Selection, released via Melonbooks, before being brought into maimai DX as part of the HARDCORE TANO*C collaboration event in Splash PLUS. Its driving bassline, rapid-fire synth leads, and relentless 190 BPM energy are hallmarks of USAO's club-oriented sound. In maimai, Big Daddy debuted with a notable unlock condition: players had to accumulate 500 km of distance in the dedicated HARDCORE TANO*C Area during a limited window from May to July 2021. The Master chart, designed by サファ太 (Safata), hits exactly 1,000 total notes at level 13+ (constant 13.8), making it a demanding stamina test that keeps pace with the track's unbroken intensity. The Expert chart, designed by シチミヘルツ (Shichimi Hertz), sits at level 12 and provides a slightly more measured introduction to the song's structure. Across all difficulties, the chart makes generous use of Slide and Touch patterns to mirror the song's frantic energy. The song has also crossed over into several other rhythm games including WACCA, PUMP IT UP PHOENIX, and QQQbeats!!!, reflecting its broad appeal in the arcade rhythm-game ecosystem. Big Daddy became available by default starting from maimai DX UNiVERSE, removing the limited-time unlock requirement.