響縁 (Kyouen) is a Touhou Project vocal arrangement performed by the doujin music circle 豚乙女 (Butaotome), best known for their high-energy blend of rock, folk, and electronic elements with distinct vocal harmonies. Originally released on Butaotome's 2010 album 縁 (Enishi), the song reimagines 少女綺想曲 ～ Dream Battle, the Stage 4 boss theme from 東方永夜抄 ～ Imperishable Night (TH08), composed by ZUN (Team Shanghai Alice). The arrangement was handled by comp (also the lyricist) with vocals by ranko, two founding members of the circle whose collaborative style defines Butaotome's signature sound. The track entered maimai as part of the ORANGE PLUS update on March 19, 2015, receiving a full set of four Standard charts. Its in-game music video was sourced from Butaotome's PVD (Pig Video Desu) DVD collection, produced by むらしん and 零花. Over the following years, the Standard Master chart underwent several level revisions, rising from 11 in its original ORANGE PLUS incarnation to its current 13, as the game's difficulty scaling evolved across DX versions. In a major refresh for maimai でらっくす FESTiVAL (September 2022), 響縁 was given a new set of DX charts with Touch-note support, designed by じゃこレモン (Expert) and Jack (Master). These charts were initially unlockable via Stamp Card before becoming available by default worldwide in September 2023. The dual-chart treatment, preserving the original Standard layout while adding modern DX patterns, makes 響縁 one of the longer-tenured Touhou tracks in the maimai library to receive a full multi-era charting makeover.