1) CSS Errors Ignore any properly made CSS3 Rules that were flagged.
2) HTML Errors
Remember, number2 errors are mostly flagged for your homepage. Number 1 (CSS) errors will be only the commonly linked CSS files for all your pages plus any embedded CSS styles on the home page.
You could have used a translate button on your Japanese page, but as it stands, current home page is not too bad for English.
1) Adding Automated Translation to Your Web Pages
2) Translation Buttons Generator Generator