The X-Ray Imaging and Spectroscopy Mission (XRISM, pronounced "crism"), formerly the X-ray Astronomy Recovery Mission (XARM), is an X-ray astronomy satellite of the Japan Aerospace Exploration Agency (JAXA) to provide breakthroughs in the study of structure formation of the universe, outflows from galaxy nuclei, and dark matter. As the only international X-ray observatory project of its period, XRISM will function as a next generation space telescope in the X-ray astronomy field, similar to how the James Webb Space Telescope, Fermi Space Telescope, and the Atacama Large Millimeter Array (ALMA) Observatory are placed in their respective fields. The mission is a stopgap for avoiding a potential observation period gap between X-ray telescopes of the present (Chandra, XMM-Newton) and those of the future (Advanced Telescope for High Energy Astrophysics (ATHENA), Lynx X-ray Observatory). Without XRISM, a blank period in X-ray astronomy may arise in the early 2020s due to the loss of Hitomi. During its formulation, XRISM/XARM was also known as the "ASTRO-H Successor" or "ASTRO-H2". Overview With the retirement of Suzaku in September 2015, and the detectors onboard Chandra X-ray Observatory and XMM-Newton operating for more than 15 years and gradually aging, the failure of Hitomi meant that X-ray astronomers will have a 13-year blank period in soft X-ray observation, until the launch of ATHENA in 2035. This may result in a major setback for the international community, as during the early 2020s, in other wavelengths studies performed by large scale observatories such as the James Webb Space Telescope and the Thirty Meter Telescope will commence, while there may be no telescope to cover the most important part of X-ray astronomy. A lack of new missions could also deprive young astronomers a chance to gain hands-on experience from participating in a project. Along with these reasons, motivation to recover science that was expected as results from Hitomi, became the rationale to initiate the XRISM project. XRISM has been recommended by ISAS's Advisory Council for Research and Management, the High Energy AstroPhysics Association in Japan, NASA Astrophysics Subcommittee, NASA Science Committee, NASA Advisory Council. With a planned launch in 2023, XRISM will recover the science that was lost with Hitomi, such as the structure formation of the universe, feedback from galaxies/active galaxy nuclei, and the history of material circulation from stars to galaxy clusters. The space telescope will also serve as a technology demonstrator for the European Advanced Telescope for High Energy