Japan 1988 Mint Bureau Japan proof coin set

(I make a mistake saying the word on the folder is chinese word where it is actually japanese word , some of the japanese word share the same character with the chinese word and i was kind of sleepy when i do the video . Please forgive me for that mistake )

Year of Issue: 1988

Material: All Cupro-nickel except 10 Yen is bronze, 5 Yen is brass, 1 Yen is aluminum

Mintage: unknown

(Denomination):(Standard weight):(Standard Diameter)

500Yen: 7,2gm: 26.5mm

100 Yen: 4.8gm: 22.6mm

50 Yen: 4.0gm : 21.00mm

10 Yen: 4.5 gm: 23.5mm

5 Yen: 3.75gm : 22.0mm

1 Yen:1.0gm : 20.0mm

Minted by Mint Bureau Japan