It's a good idea but I think it's missing a lot of feedback to have the player know what they are doing. For example, you can show the player where they can drop their items, or give them a toast when they do something they can't do (use a fruit if you have only one of them).
Other then that, the idea of having your fruits be a resource, that you either save or use during the battle can definitely have some interesting levels to play around with.