Pretty good game so far, clever use of the characters available in the one piece canon.
Got a bit of a theory on what Mc's fruit actually does. The "Heart-Heart" fruit (name pending) so far includes healing, healing others, controlling/persuading people in a positive manner and grows in power with experiencing lust with another (Though this might just be from practice from the last point) All these action are typically associated with hearts in media, be it Heath for the healing, affection with Mc's persuasion or lust being a source of power. So he seems to hold control over the meta-physicals idea of a "Heart". Maybe his awakening lets him literally see into the "heart" of someone at will.
Also, not sure if this is a bug or deliberate for balancing purposes, but the "Potion Addict" does not seem to work in battle, only the field. If that was intentional, then what ever, just wish I knew before I dropped 4 levels into it.