I already had so much nice and well-prepared food. And it is not so expensive as I feared.
For lunch I go to a diner near IAMAS. Riceballs with sidedish + miso soup + coffee = 750yen ≈ €4,5 ≈ 42sek
Also, I had a lot of okonomiyaki of course. One of my favourite Japanese dishes and for my welcoming party, the CMC/IAMAS staff cooked okonomiyaki specially for me. Very nice of them.
It's just slightly problematic to find vegetarian food. So I do eat seafood and fish while I'm here. Also I wouldn't want to miss out on the excellent sushi.