I drew Poseidon's parents as gijinkas.
Paulo is a botanist(plants) as well as an entomologist (bugs). He's fairly flirty, but his heart belongs to Tsuna. He's really passionate about his work and findings so he tends to go off on rants about his work.
Tsuna works as a marine biologist in Liliycove. She over-looks the health of the local coral reefs and the local animals as well. She's rather laid back and gets really involved in her work. She once was a contest star in the past, the money she earned from her winnings went towards her college education. She still gets stopped once in a while for an autograph.
Due to their work, Paulo and Tsuna don't get to see each other very often. Poseidon actually came about because they got drunk at a conference (after the main deal, scientists like to party too) and well, I'm sure you can assume the rest.