Japanese

Japanese is the offical language of Japan.

Appearances in The Big Bang Theory

 * In The Rhinitis Revelation (S5E06), the waiters in the sushi bar welcome the guests with Japanese " いらっしゃいませ" (pronounced as " Irasshaimase"), meaning "welcome".
 * In The Hawking Excitation (S5E21), Howard rejects Sheldon's request to see Stephen Hawking in several lanugages, including Japanese "いいえ" (pronounced as "ii-e"), meaning "no".