here is a snippet from another forum that I frequent:
In my highschool you can take Japanese has your language class. This would be my 3rd year of Japanese. I know hirgana and katakana. I already know 100 kanji characters and thier meanings. I am much better at writing Japanese than speaking but I still can speak as much as I know ...excess omitted... The hardest part of learning Japanese, to me, is learning kanji. There are so many freakin' meanings for one kanji. It took 2 years to just learn 100.
From your age and your post, I'm guessing you're probably going to attend high-school japanese classes for the next few years. The quote above is about how fast Japanese classes move in high school - excrutiatingly slow. It won't be until you get some advanced japanese classes that you will realize just how slow things go in high school. in One semester of Japanese at my school, which has a decent (but not great) program, I learned what he was taught in 2 years.
After studying for 2 years and acing every class (including the highest upper division class offered at my school taken concurrently with the fourth semester class), I took a 5-week trip to visit Japan and stay with my Japanese friend's families. I also went with the intention of seeing the Waseda campus, as I plan on applying to study there for a year starting next fall.
Spending some time in Japan and hanging out with Japanese college students (my friends), professors (their parents) and the older generation (their grandparents), I realized one big thing about my level, I didn't know jack; Vocabulary, kanji, katakana (you need to read it incredibly quickly), even modern culture, which i spent a lot of time reading up on over the past few years. I felt like an infant learning to crawl. I had a lot of fun, and I was able to survive (function is an overstatement), but I returned home humbled. This is after two years of fairly intense classes. I'm going to do my best, and I speak, read and write Japanese every day, but I do not expect to be ANYWHERE near fluent by next fall. I'll be happy enough to pass the 2nd level JLPT (4 levels, 1 being the hardest).
I'm wondering, you say you're 'still studying,' how far along are you? where are you learning from? what is your motivation? what books will you be using? do you know any native speakers to practice with? Short of being immersed in the culture, 5 years is not going to be sufficient to enter college as a Japanese student. I have two Japanese women watching me write this; one is a Student from Waseda on an exchange program, and the other is here to go to college and earn her degree here in the states. The latter says that taking classes in a foreign country for natives is the hardest kind of class, she has to do a lot of extra work just to try and understand the assignments, let alone function on the same level as native speakers. She has been studying English since her first year of junior high school; that's 3 years in junior high (including cram school), 3 years in high school, and year in various english language schools here in the states before she started college. She's not dumb by any means, what she is doing is incredibly hard.
You grew up in America, and I don't know what you know about Japanese culture or Japanese history, but you want to go to one of the best private schools in Japan the same as a native? You aren't talking about a program for foreigners to enter, you want to be a Japanese student amongst Japanese students... This is being dictated by the Japanese girls now:
You will never be treated as a Japanese person; even if you are accepted as a Japanese student by the school (which requires you to pass a test that the natives spend years studying for), people will still treat you like an exchange student. Moreover, you will be expected to function as a native Japanese student in your classes. Japan is probably one of the hardest cultures to assimilate into; no matter how good your Japanese is, no matter how good your understanding of their culture and history is, you will still be a foreigner...
back to me, I don't especially care to translate my first post, I am sticking to my assertion that once you have achieved a level of understanding where you can read it, you will understand what I mean. If you wish, explain your plans to your teacher and show him my post. I would very much like to hear your response to it, but I want you to understand the gamble this plan is...