Fun Fact: In Japan, May 16th is National Cleaning Day (Osoji no Hi), where citizens strive to have a clean nation by engaging in collective cleaning activities ranging from homes, streets, parks, shores, and rivers.by johnataylor on TwosFun Fact: In Japan, May 16th is National Cleaning Day (Osoji no Hi), where citizens strive to have a clean nation by engaging in collective cleaning activities ranging from homes, streets, parks, shores, and rivers.