Below is an IJAAF winter pilot's one-piece uniform recently on-sale on the Japanese ebay. Not much is known about Army pilot uniforms; this is probably a 1941 issued uniform. Unlike the Navy uniform featured in the previous posting, I'm not 100% sure this is an original, not a replica, uniform. Most probably is original and it seems the previous owner used wore to paint his house. Unless! this is aircraft paint!
And this a photo from the Arawasi collection featuring Army fighter pilots, wearing the above uniform, during training; probably in Akeno.