I'm glad to hear that
so can you tell me how's the exam , interview or something like that . Or how's your preparation for this scholarship test ?
Are you fluent in japanese ?
I am not so sure how relevant this will be for you (since I applied through graduate school) but here you go.
So for me I went through the university recommended route. Which I feel is a lot easier than the embassy recommended route because there is not often an exam or many interviews.
I applied to todai just like you apply for any school. You need letters of recommendations and write essay. The only thing a bit out of the ordinary was that I needed to contact a professor in order to get accepted into his lab since that was required for graduate students.
For undergraduates that is not an issue since they don't expect you to do research. If there is an exam it will likely be on the relevant topic to what you will be study (for example if you want to do physics they may give you an exam on math and physics)
However if you apply for a international program and the medium of instruction will be english, you will likely need to submit an english proficiency exam score like TOEFL. This only applies if you come from a school where the medium of instruction was not english. If you come from an english speaking country or school, you don't need to submit such exam.
You might need to submit SAT or other similar/relevant standardized test score too. (please check the application guidelines of whatever school you apply to)
For embassy recommended you will need to do an interview at an embassy, and they have an exam in Japanese, math, and I think english and maybe science. Since I never had to take the exam, I can't give you an exact measure of the difficultly but I have heard mixed reviews (some people say it is easy and some people say it is hard) and likely depends on how much people your embassy will accept each year. For the interview, I heard that they want to know why you want to go japan and you should talk about why the school or schools and major you chosen are special for you.
Given this is based on a perspective that mostly researched graduate school application procedures, I highly recommend you look at the admission guidelines on your embassy webpage or the admissions section of the school website .