Made by the serious company. Anything they make is seriously potent, like deus-ex potent. Basically they're a tool used by the author whenever they need any seriously(get it?) over the top products to appear in universe.
Besides, if we're talking realism, Shizuka would've never bounced that high on a trampoline if she's really light. Trampolines use your own mass and momentum to bounce you, so she should've been like if you threw a feather into a trampoline: nothing. But I guess maybe it was a serious trampoline too...