Chōgei (ちょうげい) is a diesel-electric submarine of the Japan Maritime Self-Defense Force, and the fifth and final member of the . Her name is written in kanji as "長鯨", literally meaning "giant whale", and this is the third use of the name, after the Meiji-era steamboat , and the Imperial Japanese Navy's .
History.
"Chōgei" was laid down on 19 April 2022 at Mitsubishi Heavy Industries Kobe Shipyard as part of the JMSDF's Mid-Term Defense Program of 2021, and was launched on 4 October 2024 after being christened. After being fitted out and undergo various trials, the vessel is scheduled to be handed over to the Japan Maritime Self-Defense Force in March 2026.