Tomodachi Ijou Koibito Miman no Ryuusenkei

Kaede failed his finals, and with make-up exams looming, a friend gives him a 'performance-enhancing drug'—which turns him into a girl. For three days, he must pass as female. Once an unnoticed guy, 'she' now experiences a whole new world of reactions... and confusing, thrilling feelings toward the friend who started it all. Before he can return to normal, Kaede faces a choice between two paths, only one of which she can take.