HAGAKIRI is an original maimai composition by Masayoshi Iimori, a producer and DJ signed to the Tokyo-based label TREKKIE TRAX. Debuting in maimai DX UNiVERSE PLUS on May 27, 2022, the track was tied to Metropolis Area 5, a themed map series centered on a sci-fi ninja narrative involving Kurohime and her elite unit, the "Five Houses" (五摂家). Players originally had to accumulate 150 km of in-game travel distance within the area to unlock it, a requirement that was later lifted starting with maimai DX FESTiVAL PLUS. At 172 BPM, HAGAKIRI delivers a high-energy electronic sound characteristic of Iimori's style, crisp percussion, driving basslines, and tension-building synth layers. The song carries no vocals, letting its instrumental arrangement carry the atmosphere of a combat-ready mechanized ninja force, as suggested by the flavor text. The title itself evokes the Japanese martial philosophy text Hagakure (葉隠), reinforcing the stealth-and-duty motif woven into the Metropolis storyline. The chart package spans from Basic (level 5) to Master (level 13+), with the Expert arrangement handled by はっぴー (Happy) and the Master chart by 翠楼屋 (Suirouya). The Master difficulty sits at a 13.9 constant, placing it at the high end of its level tier, and features dense clusters of Slide and Touch notes that mirror the track's relentless pace. In maimai DX FESTiVAL PLUS, the Master chart was briefly rated 14 before being reverted to 13+ from BUDDiES onward.