Ethan  lives in a house that is built into a cave, basically an underground house.  He gets out of the house by opening the

The entrance after you use the trapdoor

trapdoor and pushing the rock out of the way.  It is a secret hideout and no one has ever found it.  The hideout is supposedly somewhere in the distant corners of the Diablo Desert. 

Ethan has a collection of swords in his hideout, among the collection is his trademarked Katchin sword.  He also has lots of money which he stole from bad guys and uses to buy cool stuff like weapons and video games.  He has a ton of gold coins.   It has three floors and goes deep into the Earth, it also has an elevator.  On the second floor is Ethan's bedroom and also the bathroom and on the third floor there are three rooms, a gravity training room, cafe, and arcade.  In the cafe, Ethan's meals are served by robots.