Boku to Kimi dake ni Seiya wa Konai  

On Christmas Eve in December, Riichi discovered that Natsumi had returned his long-standing feelings for her. However, his joy was short-lived as she tragically passed away right before his eyes. When he came to, he realized that saying "I love you" caused time to rewind back two days. Despite his efforts to avoid confessing his love for Natsumi, she would always repeat her declaration and die again. Will Riichi be able to break free from this tragic cycle and secure his future?