Is it possible to make a fat mod for Tsugunohi?

Just anted to know if it’s possible to add sprites, lines, or even new stproes to the game begpre I even remotely attempt to make a fat mod for ot.

For this: Tsugunohi on Steam ???
I don’t really see why anybody would want to in particular, but without actually owning a copy myself I can’t really say how open to modification it could be.

Meh, just wanted to use it to learn codig a stuff