Yuuri took up compensated dating thanks to her broken family life.
She had no father and didn't want to go back home to her mother.
One day she was contacted by a certain client who offered her
a place to live, and so she headed to his hotel room...

Mai, on the other hand, left home on a whim.
Trapped on unfamiliar streets and harassed by strange men,
it was Yuuri who finally saved her.
Thinking she'd found a friend, she got in touch with her client.

That's when Mai has her first compensated dating experience...
and a plan is formed to get back at her (Mai's) father...

[From DLsite English]