Well I'm french and never been to Japan, so I'm not too used to these kind of questions asked in planes and all, as we travel freely in Europe.
As no one offered an advice yet, I'll tell you what I would do: first, I would keep a very low profile about the drugs: don't bring any, especially if you don't plan on staying for a long time: if it's only to avoid sleep problems, well you might try to resist for the duration of your stay don't you think ?
When I went to the States as a teenager, we had the same kind of form to answer to, and our guides told us that it's totally crazy to even think we can tick a checkbox and get away with it: it's basic filtration, if you answer yes to any of it, you'll be blocked or interrogated. They are utterly useless, and should be seen as a warning, not an honest interest in your habits. Maybe it was wrong, or very different from the Japanese one, but I would suggest you to avoid answering yes to any negative question ...
Also, since it's your first time, I'll tell you what I think about the interview process: I've been to Australia and the USA, and well... they just ask you what you intend to do, where you'll live and how long you plan on staying for. Don't worry it's very basic, at least it was 7 years ago in these countries, Japan might be a lot different.
What I try to say with this, is that if you're a plain tourist whose only intend is to visit some temples, you shouldn't worry too much, don't bring shady medicine (I had troubles at the french airport when they saw I was bringing french cheese as a gift for my hosts in the US so really, don't bring medicine unless it's vital
) and behave very calmly. They might try to scare you (when leaving the States, a big lady yelled at me because I was slow to understand I had to leave my shoes and put them in the scanner) to see how you react (and it was not so long after a french ***** made a joke in a plane's toilets saying he was "dropping a bomb" to the waitress asking him what he was doing for such a long time in there - I suspect they wanted to provoke us a bit after that
).
Anyway, sorry for the lack of concrete information about Japan, but since it's your first time overseas, maybe my advice can help you a little