不毛！ (Fumou!, meaning "barren" or "fruitless") is a niconico Vocaloid track by the producer ぽてんしゃる0 (potential0), who handled composition, arrangement, lyrics, and the music video. The song features dual vocals from GUMI and IA, a pairing less common in the VOCALOID scene of the mid-2010s, set against a frantic electronic arrangement at 200 BPM. Originally released on potential0's 2013 album 吟風弄月 (Ginpuurogetsu), the song debuted in maimai ORANGE on February 5, 2015, and has persisted through every subsequent version. Its lyrics are a whirlwind of compulsive word lists, cascades of 予-prefixed nouns (予想, 予防, 予兆, expectation, prevention, omen) answered by 虚-prefixed nouns (虚構, 虚像, 虚言, fiction, illusion, lie), all building to the shouted refrain "不毛！" The structure lands somewhere between absurdist rant and cynical pop, with the opening count "壱、弐、参、死" (one, two, three, death) immediately signaling the song's darkly playful tone. In maimai, the standard charts were designed by 某S氏 (Expert) and はっぴー (Master). The Master chart has undergone notable level revisions across versions, starting at 11 in ORANGE, dropping to 10+ in PiNK, then climbing through 11, 11+, 12, and settling at 12+, making it a useful case study in how the game's difficulty scale has recalibrated over the years. The in-game music video is a slightly censored version of the original PV, with the word "FUCK!" edited out for arcade display.