"Congratulations on graduation, just like 5 years ago..." I continued my 5-year-long affair with my son's friend, Kitayama-kun. It all started 5 years ago when I discovered my husband's infidelity. Kitayama-kun comforted me with a gentle kiss. Not wanting to disturb their exams, I waited until graduation day. Then, responding to Kitayama-kun's feelings, we became intimate. From then on, we reunited under the watchful eyes of my husband and son, but our relationship changed when Kitayama-kun got a girlfriend...