ノイローゼ (Neurose) is a Vocaloid original song by producer 蜂屋ななし (Hachiya Nanashi, also known as Yuuri Kuriyama), written for the voicebank flower (v flower). Released as a self-produced single in 2020, the track arrived in maimai as part of the DX UNiVERSE update on December 24, 2021, under the niconico & VOCALOID genre category. The title "ノイローゼ" transcribes the German word Neurose (neurosis), and the lyrics paint an unflinching portrait of a relationship in its death throes, circular arguments, emotional codependency, and the hollow rituals of saying goodbye. Phrases like "返してくれよ、捧げた命も全部可哀想" ("Give it back, even the life I dedicated, how pathetic") and "サヨナラと同時に二度と誰も愛せないな" ("The moment we say goodbye, I'll never love anyone again") capture the raw, self-aware bitterness that defines the song's atmosphere. The music video, produced by sakiyama, complements this tone with striking visual imagery. Musically, the track is driven by a relentless BPM of 200, pairing aggressive electronic elements with live instrumentation, guitar by Nagasaki, bass by tmsw, and piano by Dossi. The production's dense, rapid-fire arrangement mirrors the lyrical spiral of anxiety and exhaustion, creating a wall of sound that feels both cathartic and claustrophobic. In the rhythm-game context, the chart receives a distinctive treatment: the Expert difficulty (level 10) was designed by Jack, while the MASTER chart (level 13.0) was designed by はっぴー (Happy), whose arrangement leans heavily into slide-note patterns and sharp transitions that match the song's breakneck pace. The track was later included in the Asian and Chinese regional releases on separate dates, expanding its reach beyond the initial Japanese arcade rollout.