During the third story, it is revealed that the Flower Kingdom is where all flowers grow and the Mushroom Kingdom is where all mushrooms grow. Mario and Luigi fall into a portal which leads to the Flower Kingdom. Paramario is met here, and he is a main character in the game.
"Let's make like a fireball and bounce!" - Paramario when he wants to go fast.
"Let's fry a clock! Time fries when you're having fun!" - Paramario when Mario says he is hungry.
"No, of course it's not time FLIES! You can't get much higher than this!" -Paramario "correcting" Mario.
Though there are Paratoads and Paramario, there is currently no known Paraluigi, Parabowser or Parapeach, along with a list of other Mario characters in the Flower Kingdom.