Well I didn't think I would ever do it, but I apologize for posting a "how do you say _____" request, of sorts.
I am trying to complete a letter (in Japanese) to an old acquaintance who I have not been able to see in quite a long time. In a sense, what I am trying to say is "Thinking about my memories of Japan, I feel very nostalgic", or just nostalgia in general. I am not sure how exactly to go about this sentiment (having only an elementary knowledge of conversational Japanese). If, however, this is something that would not sound natural to a native speaker, or something two Japanese friends would not really write in a letter, I would prefer not to use it.
Now, where everyone else comes in:
So... after thinking about the term "nostalgia" and how a more complex feeling is expressed in language, I am now really curious to learn how other languages express (or do not express) this feeling. So, if you have a moment and are interested, it would be wonderful to learn the different ways people can express this feeling of "longing for the past", etc. :)
EDIT: thank you very much for your (quick) responses! I have also heard that word used quite often, so I am so glad to finally learn the meaning... thank you.