[Reducing Mosaic]SSIS-247 I gave her a one-month grace period, but she was obsessed with another man. So I completely stole my long-time crush, my best friend's boyfriend.

This is a story about stealing a boyfriend from a best friend. Best friend Nagi was infatuated with another man despite having a boyfriend named Taiichi. She had feelings for Taiichi but decided to step back because they were best friends. However, seeing Taiichi's lonely face made her unable to bear it, and she blurted out, 'Why don't you just break up with her and be with me?' A month later, she heard that Nagi was going on a trip with a senior, so she gave her some leeway, thinking if they reconciled, she would give up. But Nagi went on the trip leaving Taiichi behind. So she decided to take Taiichi for herself, body and soul.