Japan plans to develop a new underwater-launched hypersonic guided missile to enhance sea-based strike capabilities.

The new weapon will be a derivative of the Type 25 Hyper Velocity Gliding Projectile (25HGP). It is intended to be launched from an underwater platform, which could include conventional submarines or large unmanned underwater vehicles. The Japan Ministry of Defense stated the missile is designed to have long-range strike capabilities and flight characteristics that make it difficult to intercept. This project is part of Japan's broader hypersonic guided missile effort, which aims to provide the Japan Self-Defense Forces with a long-range stand-off weapon capable of traveling at speeds exceeding Mach 5. In the same budget document, the Japan Ministry of Defense allocated JPY14.2 billion for continued hypersonic guided missile development and JPY167.3 billion for the acquisition of hypersonic missiles and associated ground equipment.