From her shy nature, Reina, who had drifted far from the college life she and her friends had dreamed of during their girls' school days, found her heart exhausted to the point where it was difficult to continue her university life. Now, during her sophomore spring break, she returned home to think about her future. Just as she was about to do so, she unexpectedly ran into her former teacher, Mizuno, from her school days, while on her way back to her parents' home...