モンダイナイトリッパー！ (Mondai Nai Tripper!) is an original song by VTuber Natori Sana (名取さな) that joined the maimai DX FESTiVAL arcade rhythm game on November 4, 2022 under the POPS＆アニメ genre. The title is a layered pun: it can be parsed as 問題ない (mondai nai, "no problem") combined with トリッパー (tripper), or broken into モンダイナイト + リッパー ("Problem Night Ripper"). A companion in-game称号 (title) unlocks the variant モンダイアリトリッパー！ ("There's a Problem Tripper!"), confirming the deliberate wordplay between affirmation and trouble. The song was composed, lyricized, and arranged by sasakure.UK, a veteran producer well known in maimai for earlier contributions including ＊ハロー、プラネット。 (Hello, Planet.), 麒麟 (Kirin), and the EmpErroR. It was first unveiled during Natori Sana's second solo event, "さなのばくたん。-メチャ・ハッピー・ショー- Powered by mouse," where it served as a celebratory original number for her streaming community. On the charting side, the Expert (10+) layout was designed by 翠楼屋 (Suirōya), while the Master (13+) chart carries a notably high Touch-note count of 121 out of 839 total notes, making it a rhythmically dense experience that demands both precision and comfort with the DX sensor panel. The Master chart was co-designed by アマリリスせんせえ with ぴちネコせんえ (Amaryllis Sensei with Pichineko Sensei).