BranchMonster said: The Japanese text above it says "yakamashii" which means simply "noisy", not "shut up".
Thus, this can't really be considered 'fixed'.
Except saying "yakamashii" in this context means you're telling someone they're being noisy, with the implication that you want them to shut up. "Shut up/Be quiet" is thus the proper equivalent English idiom, and the Finnish translation should reflect that.