Ultimately, I cannot recommend this manga. The MC is flawed (which is okay) but completely unlikeable. He's just so fucking stupid even though the first chapters built up to be smart.
Doesn't this kind of OPness get boring for anyone else? There's no fucking structure in this story, and it's basically self-insert slice of life and nothing else
@Deathhappens
realistically, impossible. Sand has a low terminal velocity, and air resistance would overpower any initial velocity. The sand would disintegrate in the air before reaching 400m at high velocity.