俺に寝取られた元カノ？、知らない許嫁、陽キャな幼馴染が迫って来る。

A little after I, Tatsuya Tateishi, entered high school, I became close with Ryoko Motomiya, whom I had known by sight from junior high.

I was on the library committee at school, and she joined the tennis club. We became very close within the first six months or so, and she confessed to me, and we started dating.

At first, we often went to and from school together, but she started morning practices and staying late for club activities, so we only met on weekends.

Then, on a weekend, after two months of not being able to meet because she said she had club activities even on those days, I saw her entering a love hotel with a man I didn't know.

I thought I had been dumped without realizing it, and, heartbroken, I tried to distance myself from her, but she, unaware that I had seen what happened on the weekend, continued to talk to me as usual at school.

I tried to show Ryoko the evidence and break up with her, but she insisted it wasn't her and wouldn't leave me.

When I became a second-year student, a girl named Reiko Tachibana (Tachibana Reiko) transferred to my high school. She claimed to be my fiancée, but I knew nothing about it.

Just then, my childhood friend, Sanae Kiritani, interrupted, demanding I make her my girlfriend.

Completely bewildered, time continued to pass...