As someone who is also somewhat "introverted" and spend most of his time indoors just playing some games and watching some tvshows/anime, what made me go outside was an outgoing person who was willing to drag me out of my comfort zone. :)

At first, I honestly don't like it as I was not used being under the sun and even walking places (going around the mall is tiring). But over time, I kind of long it. I think what you really need is a person willing to teach you the world outside your room. :)