async is the nineteenth solo studio album of Japanese musician Ryuichi Sakamoto and his first one in eight years since Out of Noise (2009). It is also his first full-length solo record since recovering from throat cancer in 2015. Consisting of a combination of bizarre interpretations of familiar musical instruments, unusual textures both acoustic and electronically made, samples of recordings of people such as David Sylvian and Paul Bowles doing readings, and everyday sounds borrowed from field recordings of city streets, async has underlying themes of the worries of the end of life and the interaction of differing viewpoints in humanity.

Promoted with two art museum installations, a short film contest, and premiering via a listening event at Big Ears Festival, async was first released in Japan by Sakamoto's label Commmons in March 2017 before Milan distributed it to other nations in April 2017. It was critically acclaimed, landed in the top twenty of the Japanese albums chart and in the top five of Billboard's American Top Classical Albums chart, and was ranked the best album of 2017 by Fact magazine. A set of remixes of songs from async, titled ASYNC – REMODELS, was released in December 2017.

An innovative reinterpretation of async, "async - immersion 2023" was released on February 2, 2024. This project, a collaboration with Shiro Takatani, was initially presented as a site-specific installation in the basement of the Kyoto Shimbun Building. The release aims to replicate the auditory experience of the 'async - immersion 2023' exhibit showcased at AMBIENT KYOTO. Audio engineer ZAK played a pivotal role in this endeavor, crafting a unique mix that seamlessly blends the ambient sounds of the exhibition space—a former printing factory—with Sakamoto's original compositions. Designed to be experienced asynchronously, the project diverges from traditional synchronization of sound and image, creating a dynamic and ever-changing relationship between the two. It reflects Sakamoto's innovative approach to music and art, offering audiences a unique, immersive experience that captures the essence of his artistic vision.