Hopefully you'll have fun! I've done a few Jams before but this is my first time doing more of the hosting/helping. I'm very much not the typical jammer mould though (Arts/Fine Arts grad with Japanese and Photography majors). Although I've always learned something completely new to me each jam I did. (I learned enough ruby do some tinkering with RPG maker's battle system for one Jam, and enough python to make a VN with ren'py).
And don't worry! While it's vaguely intended primarily for jets, it's really for anyone in Japan and too much time in summer!
I'm excited to play what you make though!