1000年生きてる (living millennium) is a Vocaloid original by Japanese producer いよわ (Iyowa), featuring both Hatsune Miku and flower. First uploaded to NicoNico Douga on December 11, 2020, the track reached 5th place in the ボカコレ2020 (Vocacolle 2020) TOP30 ranking, a prominent annual chart for the NicoNico Vocaloid scene. The title translates roughly to "living for a thousand years," and Iyowa handled every aspect of production single-handedly: lyrics, composition, arrangement, illustration, and music video, reflecting his distinctive do-it-all creative style. Musically, the song sits at a steady 100 BPM with a mid-tempo, slightly surreal pop arrangement. The interplay between Miku's and flower's vocal timbres gives the track a layered, conversational quality that has resonated widely in the Vocaloid community. In maimai DX, the song arrived on September 14, 2023, as part of the BUDDiES version update under the niconico & Vocaloid category. The Master chart (level 13, constant 13.4), designed by はっぴー (Happy), offers a dense but navigable challenge for its level bracket, while the Expert chart (level 9, constant 9.0), designed by サファ太 (Safata), features a notable concentration of Touch notes at 50, one of the higher Touch counts on a level-9 Expert chart in the BUDDiES era. A DX Collection tie-in pairs the song with パーフェクト生命 (Perfect Life): clearing both tracks with ALL PERFECT in a single credit unlocks the title "完全無欠ヒューマン" (Perfect Human).