隠然 (Inzen) is a vocal Touhou Project arrangement by the doujin music circle Butaotome (豚乙女), featured in maimai FiNALE since its release on February 22, 2019. The song reimagines "秘匿されたフォーシーズンズ" (Secret Four Seasons), the stage 6 boss theme from 東方天空璋 〜 Hidden Star in Four Seasons (the fifteenth mainline Touhou game), associated with the hidden goddess Okina Matara. Butaotome, a prolific circle known for energetic rock- and folk-infused arrangements, produced this track with arrangement by comp and vocals by ranko. It originally appeared on their 2017 album あやかし横丁. The title 隠然 (roughly "concealed" or "hidden in plain sight") reflects the song's thematic connection to secrecy and the four seasons, the lyrics trace the natural cycle of blooming flowers, falling leaves, and winter snow as metaphors for things deliberately kept hidden. In maimai FiNALE, the song was accompanied by a moving background image of Okina Matara; this was changed to a static jacket display when the title transitioned to maimai でらっくす. The chart set spans all five standard difficulties, with the Re:MASTER chart (level 13, constant 13.4) designed by 某S氏 and notable for its dense slide-note patterns and 734-note total, making it a demanding play for experienced Touhou chart enthusiasts.