Jerry is an NPC by the sea near the first town. He doesn't say much (unlike the real Jerry) and looks exactly the same as all the other NPCs
Unfortunatley, it turned out that nurse joy was secretly a man trapped in a woman's body. Luckily, due to the latest sex change technology this has been rectified. Mr Joy can be found in all Pokecentres across the region.
Merchant is a guy who sells stuff in the first town. He's a bit of a rip-off. Nuff said