Basically for the unzipping thing you need to change the settings of your unzipping program to work with the Japanese language so that it can properly handle files with Japanese characters in their names, if you don't have it set to Japanese some of the files are likely going to be processed incorrectly which may cause some issues with the game. I'm not sure if it matters for this game but it was all I could think of if nothing is wrong with your RTP files or computer.
Something I didn't think about previously is the resolution, did you try to change the resolution of the game on the main menu? A lot of people, myself included, have had issues after trying to change the resolution.
I am not super knowledgeable about computers but the only other problem I could think of is your graphics card/program not interacting properly with the game. Maybe try updating your drivers?
Sorry if none of that helps, if nothing else maybe just wait till the next update and see if the problem still persists.
Oh, I didn't know unzipping thing was so complicated! I will look into it. thanks a bunch! hope it will fix it.
I am just doing Alt+Enter to get the game to a fullscreen. I will try using in game settings next time.
Well, as for GPU, I am indeed having problems with my GPU. "Sudden freeezes for 30 60 secs and sometimes complete GPU failures" I will try to fix that as well that might be the problem.
For updates, I was having these issues at previous versions and I thought it will be fixed in next update but it didn't and I really want to play the game.
But thanks a lot for insights! I really appreciate it! Even if couldn't fix the problems, I am still learning things along the path!