 Complete the following phrase:   was an aircraft carrier built for the Imperial Japanese Navy IJN during the mid-1930s. A sister ship, , was intended to follow Sōryū, but Hiryūs design was heavily modified and she is often considered to be a separate class. Sōryūs aircraft were employed in operations during the Second Sino-Japanese War in the late 1930s and supported the Japanese invasion of French Indochina in mid-1940. During the first months of the Pacific War, she took part in the attack on Pearl Harbor, the Battle of Wake Island, and supported the conquest of the Dutch East Indies. In February 1942, her aircraft 