Recruiting Oniichan by Sodomutogomora

The protagonist is a freeter.
Job to job, gig to gig, he pays the debt his parents left behind
in a life comprised of go-nowhere temporary work.

"We're looking for guys!" says a flyer that catches his eye.
Another day, another gig. He calls the number and is told to go
at a certain location.

That location is a lavish western-style house.
Two pretty girls are waiting for him.