Downer-kei Joushi wo Koi ni Otosu Houho

"I'll go out with you for a period of three months." Today, exactly three months after being told that, the romantic relationship between Shijima and Inoue, his boss at the company, came to an end. Inoue's relationship started out as a one-sided favour, but they ate together, went on dates, got close to each other, and even when I kissed him, he didn't refuse me.. There must have been moments when the two of you shared your feelings while dating. Unable to give up, Shijima continues to approach him, but he doesn't falter at all. It seems like there's a reason why he can't date Inoue..?