When she was young, Mitsuki was tutored by Imai Yoshinobu in private, thanks to her sister Chizuka's arrangement. Although their classmates had a pleasant relationship, Mitsuki couldn't help feeling hopeless and envious in trying to win Imai-san's affection while her sister was present. However, when Chizuka broke up with her boyfriend, Mitsuki saw an opportunity to trick Imai-san into thinking her sister had found a new love interest. To her surprise, he agreed to date her instead. However, Mitsuki is now struggling with the guilt of their relationship, which was based on a lie. In addition, this volume includes the one-shots "The After School Lair" and "G-Line Romance".
