[うおごころあればみずごころ, uogokoroarebamizugokoro](exp) (id) if you do a favor for somebody, you will get a return favor; if a fish is friendly toward water, water will be kind to the fish too; mutual back-scratching[Add to Longdo]
[みずごころあればうおごころ, mizugokoroarebauogokoro](exp) (id) (See 魚心あれば水心) if you do a favor for somebody, you will get a return favor; if the water is kind to fish, the fish will be friendly toward water too; mutual back-scratching[Add to Longdo]