Japanese pesos?
Japan’s currency isn’t pesos, right? We’re more than certain that it’s yen. We even Googled and Binged to make sure! However, the image doesn’t lie, so we have no idea as to why the Japanese government would print pesos.
The OP was just as confused as we were. They originally thought that this was fake money for a Monopoly set or something. However, one commenter pointed out that Japan printed pesos for the Philippines during their occupation in WW2. They’re probably not spendable in today’s market, but these bills might still fetch a pretty penny from a collector.