The Newfoundland cent is probably the most valuable (a dollar or two)... they had low mintages and have a small but dedicated collector base.
The 100 yen has an exchange face value of about US $0.88. I can't see the year on it, but this coin was issued from Hirohito 42 (1967) - 63 (1988) and from 1989 to present under Akihito (would be years 1 - 27). If your coin is from Hirohito, it will command a slight premium in that grade. If it is from Akihito, it is worth face only.
Finnish coins after the 60s are not especially popular or valuable.
With very, very few exceptions, circulated wheat cents are worth no more than 5 cents each.