....?That's true, in fact I think he's a moon person, because of the fascination for masks and the physical look
Um. What reason to we have to suspect there's such a thing as moon people or that they have anything to do with masks? The Happy Mask Salesman heard about Majora's Mask and sought him out, so it seems like he lived on earth and knew the lore. If he was from the moon, wouldn't he have only appeared after Majora's Mask started calling the moon?
Exactly. Except the Happy Mask Salesman actually operated a store. You don't build stores in places you don't live. A store is a long-term thing. Other merchants will sell on the road, like the Goron Merchants did.Don't travelling salesmen generally (well, maybe more like half the time) sell things away from home? Do the Gorons in WW live on their rafts?