First the game is great, the models and animation are outstanding, that said, hearts should be made easier to obtain because they're necessary for resetting a girl's route should you fail
It makes no sense at all to make them necessary, but rare at the same time. Been playing the game for a while and only ever found one
Hearts aren't even that hard to find they're everywhere in some locations, then there's the forest i usually gets 1 out of 3 tries if im Lucky I'll get 1 for 2 consecutive times. Your luck determines how hard it will be to get heart or the starfruit which can be increased by going on the same forest
My technique is saving the game before i try to get anything in the forest, reloading it, if i didn't get heart, I'll try the starfruit if i didn't get any of the two, i always try to increase my luck. Increasing your luck also helps win in the gamble which give you 1000 for first prize but mostly only 250 or 450
