In case you're wondering, the "Japanese" section of the shirt has a mixture of actual Katakana (usually used for "style" or foreign words) and Hiragana (used for native words and [grammar] case markers). Plus, random shapes that look somewhat like Katakana. Some appear to be backwards Katakana, while some are simply made up (like the "R" character).

Also, the shirt says you need to turn you head to read it... But traditional Japanese, which was written top-down and right-to-left, was readable without turning your head. T L K
H I I
I K N
S E D
_ _ A

(edit: Vertical text is weird in Markdown)

I realize it's meant as a joke. But if you know Japanese, even if only how to read the non-Kanji, alphabetic characters (Katakana and Hiragana), it borders on lame. Especially since they faked a bunch of the characters.