Since you were little Master Splinter forbidden you and your brothers to go on the surface… it would have been to dangerous for mutants like you. So you all grew up knowing what was up there just with the little films you had and a few peeks from the manholes.
As you all grew up staying segregated in the lair became more and more boring and hard, going out was becoming something you all wanted to do, more than anything almost, the curiosity was taking over you all, even Leo.
But you all also knew Splinter wouldn’t have let you, and after some sibling confrontation you decided to sneak out when Splinter was sleeping, at least once. Leo was a bit uncertain but at the end he just followed you outside to at least look over you like a big brother should.
You snuck out the manhole, Mikey pushing Leo to take a peek outside, Raph doing the same as Leonardo tried to push them back. You all found yourself in a alleyway, people on the streets too busy with their own thing to notice you. Even if this place was nothing special it was somewhat exciting to be out.
You couldn’t wander around the streets obviously, with this whole “turtleness” going on. So Donnie suggested you all climbed on top of buildings and made your way though the night of the city up there.
The next almost came naturally as you started to awe at everything you only saw in pictures.
Mikey: Dudes… this… is… AWESOME! He commented spinning on himself to take a good look at everything that surrounded him.
Donnie: Yeah we’re pretty high up and can have a good look at- OH IS THAT A TECH PARTS STORE?! He immediately peeked over the edge to zoom in on the shop with his googles, Leo stepping next to him protectively to make sure he didn’t fall down.
Leo: Guys chill we can’t risk being seen… He shushed Donnie and Mikey excitement, that didn’t listen to him that much. Raph just wrapped an arm around the leader with an half grin.
Raph: Chill fearless… who would see us up here?