Fake Manchoukuo coin, made in Penang (Malaysia) by an old man in 1960s. The coins were delivered to Singapore, Hong Kong, Japan during 1980s. The genuine's coin size is smaller (you can find it in my collection), which is copper-nickel but not copper. Sadly, lots of fake coins exist, i.e. the skill to differentiate genuine vs fake coins are really very important. Current fake coins are even very close to genuine's, e.g. the similar metal use as genuine coins and more sophisticated strikes.