All are from Japan, 50 yen, 10 yen, the brass I think is 5 yen, and 1 yen aluminum. You can find out how to read the Japanese online. It details the emperor ruling when the coin was made and how to decipher the Japanese characters, that’s how I learned about 8 years ago.
From top to bottom - Showa 42, 45, 62, and 63. Add those numbers to 1925 to get the year in our calendar.
Showa (昭和): Started in 1926 (Add regnal year to 1925) Heisei (平成): Started in 1989 (Add regnal year to 1988) Reiwa (令和): Started in 2019 (Add regnal year to 2018)
@Mark1971 - Everything has pretty much been said already about these coins. They all still circulate in Japan today. Regnal year in Japan now is Reiwa 8 or 令和八年 or 令和8年. "Japan" is represented on the coins by the Kanji: 日本国 or "ni hon koku" In case you're interested in the Kanji representations of the denominations: 一円 - 1 Yen ("ichi en") 五円 - 5 Yen ("go en") 十円 - 10 Yen ("juu en") 五十円 - 50 Yen ("go juu en") The exact dates are 50 Yen - 昭和四十二年 (Showa 42) - 1967 10 Yen - 昭和四十五年 (Showa 45) - 1970 5 Yen - 昭和六十二年 (Showa 62) - 1987 1 Yen - 昭和六十三年 (Showa 63) - 1988 Adding 1925 will work within the regnal year of Showa (this was the regnal name for Emperor Hirohito, who ruled during WWII), but it won't work for other regnal years that are not Showa (in case you come across Japanese coins from other imperial reigns).
Having recently been to Japan I recognized them all, but didn’t know about the years. There’s also 100 and 500 yen coins. 100 10 and 1 were the most common in change. Didn’t see many 5. A new 500 is a big beautiful coin, and a lot of money, almost like a $5 bill in the US.
Picked this up 10 years ago from cruising relatives. It is truly a lovely coin. In 2016 I graded a lot of coins from circulation AU58/58+, but if I regraded it now I think it would be MS61 or better. The mirror surfaces on both sides are exquisite.
I got a few nice ones in change but on closer examination of photos I took, decided they were AU so I spent them. It was nice that we could pump all those 10s and 100s into the train ticket kiosks. It really is a nice looking coin, with a cameo effect. Probably should have kept this one.
