Buying a Classmate Once a Week, Vol. 1 (light novel)

Once a week, high schooler Shiori Miyagi pays her classmate Hazuki Sendai five thousand yen to make the girl follow her orders for the afternoon. Their sessions start with normal activities like snacking and chatting...until a mood strikes Miyagi, and she gives Sendai commands that veer into risky territory. No matter the order, Sendai follows, even if it means licking Miyagi's feet. Yet after half a year of engaging in this secret dynamic, neither girl calls the other a friend. So what does that make them? And with their last year in high school looming, is their relationship doomed to crumble?