I'll send this to our language expert, SraJMcGin. She may be able to help you.
This sounds fascinating! Having studied 19 languages and taught 5, they have been my life. Consider this: how can you communicate without language? Of course, you can with gestures, body language, facial expressions, etc. Have you had ANY ideas or is it pretty much “open?” Not knowing more about your interests and this particular class, let me throw out a few things that might interest you:
if grammar interests you, developing language packs
history and classification of the Japanese language, regionalisms, dialects
if sounds, pitch interest you, morae, vowels, consonants, phonology, intonation
the writing system(s)
how to best learn Japanese
Japanese poetry, haiku, etc. (illustrated?)
vocabulary words in other languages derived from Japanese
Purdue University has an interesting project for Japanese E-mail
some class projects (not very sophisticated but fun to see and I love the music): http://www.youtube.com/watch?v=JUDpsyEdvqI
beautiful music on this one and if you play a musical instrument you might work that into your project: http://www.youtube.com/watch?v=p9IQBuaTLCM
some of my students came up with some fascinating projects that they did alone, or in a small group. My main purpose was that they do something they really enjoyed BUT involved the class, attempting to touch the 5 senses. That meant that some did visual projects, others aural, still others tactile, one involving perfume that touched the olfactory and others involving food for taste. One young man who became a chef and later had his own restaurant, took several days, had his mother and aunt pushing steam trays for an entire meal. He had presented the menu, vocabulary the day before and the day after even had a quiz! That’s just ONE of many outstanding projects and believe-you-me that most were far more creative than I could have done!
So, consider your interests, hobbies, “brain storm” and if it is fun for you, it will be fun for your classmates!