Re-application for tourist visa (etc.)

I had tried to search about this matter but hadn't found anything...

I want to go to Japan for about 2 months and 1 week in summer. Reason: 6 weeks of studying in language school (I have obtained enrollment documents for them...), 1 week of travel, the rest (2-3 weeks) stay at friend's place in Tokyo (...but I obviously have no documents for this travelling, except addresses and flight ticket). I need to obtain a tourist visa. This said, I have few questions...

1) Since my nationality is required a guarantor, I, theoretically, shall need a guarantor. But I have permanent residence in a country with NO visa requirements with Japan. In the language school they assured me that in case my citizenship needs a guarantor BUT I have permanent residence in the country without this unbelievably annoying stuff required, I don't need a guarantor as well. They also assured me that it always worked that way even for students with my nationality who lived in countries with no visa requirements (I'm Russian living in Czech Republic).
Since, as I said, the country I live in never deals with the shortest tourist visa stuff, I'm afraid they just might not know about this exemption. (This is not a joke, I'm pretty serious about this presumtion).
Do you have any experience to share or any advice?

2) If I fail to obtain the tourist visa... Can I re-apply immediatily? I know the reason won't be told but I just can re-check all the documents, fill in information about my stay even more precisely and add several thousand dollars in the bank account (they check it...) or whatever and apply once again. I just want to know whether it should be possible without any ''banned'' interval to re-apply right after denial. (I have less than 3 months left before departure...).

Thank you very much!

It only counts what Passport you actually have. Only with a Passport of the Czech Republic you can enter Japan without visa. With Passport of Russia you can only enter with visa. The Japanese authorities are not interested in your country of residence but only in your nationality as mentioned in your passport.

I know about this, that's why I asked about guarantor etc., because I need visa.

Well, I'm going to Japanese embassy on Monday so, hopefully, I'll get some info...