You can explore all the school grounds, and the outskirts, where you will discover quite a few interesting stuff. There is a pool, a gym, a cafe and basically anything you might expect from a Japanese high school. The thing here, is that you can have tons of interactions with your surroundings like picking up balls and throw them, sodas, weapons, school bags and bodies (and not only).
The fun fact about this game (which other times can be plain painful) is the object physics. When you pick up a body and drag it around, I could never help but laugh at the ridiculous way it’s moving. Once you’ve discovered the location of the helicopter tho, I think you’re set. Try having some fun now, will you? It’s not every day that you get to experience that.