It's not exactly taught in every American high school, mainly because it is more difficult to learn than Spanish, French or Italian. Japanese can be found on the college level, especially when business majors are looking to work for a Japanese company. A friend of mine who is CPA learned Japanese for his job. At any age, it is a challenging language.
RESOURCES
About Japan-from the Japan Society; from Haiku to Japanese architecture
American Association of Teachers of Japanese
Basics of Japanese Culture
The Japan Foundation- featured Websites and resources
Northeast Council of Teachers of Japanese- covers the east coast of the United States
LESSON PLANS / ACTIVITIES / VIDEOS
Basic Phrases in Japanese- mp3 files for students to listen
Complete Guide to Japanese
Japanese Foreign Language Worksheets and Printables for Kids- from Education.com; beginners
Japanese Grammar/Expressions Lessons- many resources from About.com
Japanese Grammar Guide
Japanese Lesson Plans- from TeAchnology- worksheets, puzzles all about Japan
JapanesePod101- large video collection on their youtube channel
Learn Japanese- flash cards, activities, videos
Lesson Plans on Japan- covers art, culture, education, geography, history, literature, politics, religion
RESOURCES
About Japan-from the Japan Society; from Haiku to Japanese architecture
American Association of Teachers of Japanese
Basics of Japanese Culture
The Japan Foundation- featured Websites and resources
Northeast Council of Teachers of Japanese- covers the east coast of the United States
LESSON PLANS / ACTIVITIES / VIDEOS
Basic Phrases in Japanese- mp3 files for students to listen
Complete Guide to Japanese
Japanese Foreign Language Worksheets and Printables for Kids- from Education.com; beginners
Japanese Grammar/Expressions Lessons- many resources from About.com
Japanese Grammar Guide
Japanese Lesson Plans- from TeAchnology- worksheets, puzzles all about Japan
JapanesePod101- large video collection on their youtube channel
Learn Japanese- flash cards, activities, videos
Lesson Plans on Japan- covers art, culture, education, geography, history, literature, politics, religion