捕らぬ狸の皮算用 (とらぬたぬきのかわざんよう): counting one's chickens before they're hatched; counting raccoon dog skins before they have been caught

counting one's chickens before they're hatched; counting raccoon dog skins before they have been caught

For someone spending or planning around a reward they have not actually received yet.

A Japanese proverb (ことわざ)