Some parts in "Marble Water" has exactly the same chords as YMO - Perspective. I think R. Sakamoto was very inspired by this song when he made Perspective.
This is early demo track of Seirou Okamoto, who composed famous game musics such as Magic Knight Rayearth (for SEGA Saturn). Posted them to FM Sound Street (DJ Ryuichi Sakamoto (YMO)) an broadcasted on 1984. 1. Gappone (On Air Feb, 14th, 1984) 2. MARBLE WATER (On AIr May, 22th 1984) 3. Circus is Coming to Town (Oct, 9th 1984 ) first 2 tracks are included on the album DEMO TAPE-1 by Ryuichi Sakamoto and Akiko Yano (ASIN: B00005FE4O EAN: 4988034201340 )