Analysis of information sources in references of the Wikipedia article "Nakajima A2N" in English language version.
The light aircraft carrier Hosho with ancient A2N fighters was posted together with the carrier Ryujo to 1st Carrier Division of the 3rd Fleet, leaving the port of Sasebo on 12 August. Arriving in the Ma'anshan Islands area, they started supporting land operations beginning on 16 August. During this period, both Kaga and Ryujo groups had opportunity to engage in aerial battles.
On 16 August 1937, six A2Ns from Kaga commanded by Lieutenant Chikamasa Igarashi, engaged four enemy aircraft over Kiangwan. Three of the enemy aircraft were shot down, one Corsair and two Douglas O-38s (sic. O-2M, as the very similar O-38s were not with CAF service) One of the Douglases was claimed jointly by Matsuba and another pilot. This was Matsuba first combat and first victory.
When did World War II begin? The answer you might find surprising. Americans might say December 7, 1941… The day the Japanese Imperial Navy attacked the American naval base at Pearl Harbor, Hawaii. For Europeans, it was September 1, 1939… When Nazi Germany invaded Poland. But in China, people will tell you a different date. August 13, 1937.