Miyako Kirishima, a university student and aspiring teacher, is a poor girl who enjoys being frugal. One day, she has a meal with Yui Nakano, her friend whom she occasionally tutors. On the way home, Yui invites her to a love hotel. Miyako is reluctant, unwilling to have sex with a friend. However, Yui cuts her off, offering her 30000 yen for sex! Subsequently, Miyako ends up in more "transactions" with her other friends at her women's university!? The curtain rises on a tale of yuri, friendship, money, and sex♡. Note: Includes 9 extra chapters.