Mako's Development Diary · A Risky Promise Episode 1 / 4
Mako makes a daring promise to her boyfriend, Kaoru, offering him sex if he achieves above-average grades on his exams. However, while a sedated Kaoru sleeps, Mako is seduced by her own brother. Overwhelmed by pleasure and guilt, Mako gives in to her brother's advances, discovering a hidden side of her sexuality while her boyfriend remains oblivious.
