 The Japanese codenamed the Midway invasion Operation "MI".On 25 May 1942, "Sōryū" set out with the Combined Fleet's carrier striking force in the company of "Kaga", "Akagi", and "Hiryū", which constituted the First and Second Carrier Divisions, for the attack on Midway Island.Her aircraft complement consisted of eighteen Zeros, sixteen D3As, eighteen B5Ns, and two prototypes of the new Yokosuka D4Y dive bomber.