The 20shi "Sozan" (Blue Mountain), known to the Allies as "Rose", was to be a very...very beefed up "Renzan" version. The concept and the artwork is from THIS site which is the ultimate what-if destination for unusual, fantasy and incredibly interesting J. planes but also tanks and ships. Check HERE for more on the "Sozan".
Don't tell me you don't feel like building one. I know I do.