しねばいいのに (Shineba ii noni, roughly "I wish they would die") is a VOCALOID track by the doujin music circle どぶウサギ (also credited as dBu), with KAITO handling the vocals. The song first appeared on the Comiket 75 release 俺の脳内ミクが一番可愛い2 ("My Brain's Miku is the Cutest 2," December 2008) and was later added to maimai as part of the MiLK update on February 6, 2018. The lyrics run through a string of petty, everyday annoyances, a spam call cutting in just as sleep comes, a fly darting into an open mouth mid-yawn, a late-night show lost to baseball overtime, each episode capped with the deadpan refrain "しねばいいのに." The deliberate mismatch between trivial grievances and an extreme response captures a specific vein of late-2000s VOCALOID internet humor, and the artist's own tongue-in-cheek comment ("There's no murderous intent. I just think they should die. A song to enlighten such a culture… just kidding.") leaves little doubt about the ironic framing. At 138 BPM and just under two minutes long, the song moves at a brisk, conversational pace well suited to its comedic structure. In the context of maimai, しねばいいのに is notable as the first song in the series to feature KAITO as the sole vocalist with no other VOCALOID or virtual singer. Its in-game music video was newly produced for the arcade release, replacing the original footage with animated sequences starring maimai's own cast of characters. Over successive DX versions the chart difficulty ratings were adjusted several times, Basic dropped from 4 to 3, Advanced rose from 6 to 7, Expert climbed from 8+ to 10, and Master increased from 11+ to 13, reflecting how the song's placement in the overall catalogue evolved. The Expert chart was designed by LabiLabi, and the Master chart by はっぴー, each bringing a different note-composition philosophy to the same source material.