Foreign characters not displaying since upgrade.

After upgrading, WP no longer allows me to have foreign characters in my posts (Japanese, in this case). Not only that, but it has gone through and rendered my prior posts gibberish.

I need Japanese text to be useable in my blog, otherwise WP is worthless for that blog.

Additionally, after the last upgrade WP put an A with a circle above it at the end of every single sentence. Is there a fix for this?