It is unknown when Minato and Kushina had met. But is also unknown if Minato Namikaze and Kushina Uzumaki are alive. If they are it would make the whole anime interesting and more worth watching...
I assume you're asking about the criteria for being a "planet" as opposed to a "dwarf planet": In the Solar System, these boil down to: 1. is in orbit about the Sun Yes, Pluto orbits the Sun (or at...