Once upon a time, an enthusiastic student of mine talked to his Japanese friend and was told that Particle Koto could be always interpreted as 'Matter'. Of course, I suspected neither my student nor his Japanese friend. However, as a matter of fact, in Japanese, can Particle Koto be always interpreted as 'Matter'? Really? Even we are foreigners, we can of course quote the research results from some Japanese linguists to verify if “Particle Koto” could always be interpreted as 'Matter' or not.