Named after a town now part of Toronto, Mimico was laid down as HMS Bulrush but was transferred to the RCN and commissioned on February 8, 1944 at Sunderland, U.K. On April 18, after working up at Stornoway, she arrived at Oban, Scotland, where she was assigned to Western Approaches Command for escort duty in connection with the invasion. She arrived off the Normandy beaches with a convoy on the day after D-Day. She remained on escort duty in the Channel, assigned briefly in September to Portsmouth Command and, in October, to Nore Command, based at Sheerness. In February and March, 1945, she refitted at Chatham, then returned to Sheerness and resumed her previous role until late in May, when she left the U.K. for the last time. She was paid off on July 18, 1945, and laid up at Sorel. Sold for use as a whale-killer, she entered service in 1950 as Olympic Victor but passed into Japanese hands in 1956 and was renamed Otori Maru No. 12. She was last noted in Lloyd's Register for 1962-63.