"CH-16" was built by Nippon Kokan K. K. at their Tsurumi shipyard, laid down on 22 April 1940, launched on 19 November 1940, and completed and commissioned on 5 April 1941, and attached to the Yokosuka Naval District. She participated in the invasion of the Northern Philippines (Operation "M") in December 1941 where she was assigned to Sub Chaser Division 21 (SCD 21) led by Commodore Ota along with , , , , and . SCD 21 was at the time assigned to Rear Admiral Hirose Sueto's 2nd Base Force under Vice Admiral Ibō Takahashi's Third Fleet. In May 1942, she participated in the Battle of Midway (Operation "MI") where she was assigned to Miyamoto Sadachika's 16th Minesweeper Unit (along with auxiliary minesweepers , , , ; submarine chasers , and ; cargo ships "Meiyo Maru" and ; and auxiliary ammunition ship ).