It seems to be implied that she's so much of a weirdo none of her other clients ever booked her for a second date until Hoshino came along. The way for this to turn wholesome is probably a reveal that Tsukita was let go from the agency at some point for persistently mediocre client feedback, but kept it a secret because she was afraid Hoshino would stop going out with her and hire a "real" rental girlfriend. She's going to do something like refund him for the fraudulent hiring fees with money from a part time job and saying farewell, there'll be a chapter of him durdling around slowly realizing that he's actually in love with her, a tearful reunion and an epilogue featuring the most ridiculous wedding celebration of all time.
Or, you know, it just keeps going on like this forever, until it gets axed and the above happens, just condensed into one chapter in a way that's much less satisfying.