Air Japan is a new airline brand under ANA Holdings Inc.. It is not a separate airline, but rather a new brand focused on medium-haul international routes, operating under the umbrella of the larger ANA Group. Air Japan will offer a simplified service with a focus on Japanese culture and quality, aiming to provide a unique travel experience that is not strictly a full-service carrier or a low-cost carrier.
same as ANA.
so far, my experience with ANA (but run by Air Japan) is good.