I, who works at headquarters, was assigned to a one-week business trip to a struggling branch. Feeling downcast about the tedious tasks ahead, I arrived to find my old senior, the one I admired during my training days, Yuki Yoshizawa... I was taken aback by the sight of her wearing a ring on her left ring finger, but I couldn't help but feel a pang of sadness seeing her as beautiful as ever, just like back then. That night, we went out for drinks after a long time, and I must have gotten drunk the wrong way because when I woke up, I found myself alone with my senior in a strange hotel...