Duo, subtitled Masami Akita & Kiyoshi Mizutani Selected Studio Sessions 1987–89, is a box set album by the Japanese noise project Merzbow. It is composed of unreleased studio sessions recorded with Kiyoshi Mizutani. Some of these recordings were used as raw material for solo releases like Scissors for Cutting Merzbow, but the original recordings were unreleased until now. These recordings mirror albums like Ecobondage, Enclosure, and Storage. The art edition comes with a bonus CD with a recording from 1979.
During the 1980s, Merzbow was divided between Masami Akita's solo works and improvised works with Kiyoshi Mizutani. Akita also frequently used recordings made with Mizutani as raw material for solo recordings. It was also during the time of these recordings that Merzbow (with Mizutani) first played outside of Japan; Russia in 1988 and Western Europe in 1989. Mizutani left Merzbow in 1989 and continues his own solo career.