Keiji Kiriya is a fictional character from the Japanese light novel series All You Need Is Kill, written by Hiroshi Sakurazaka. He is a young soldier who finds himself caught in a time loop, reliving the same day during a war against alien invaders known as Mimics. Each time he dies, he wakes up to face the same challenges, forcing him to learn and adapt to survive. The story explores themes of courage, sacrifice, and the struggle against overwhelming odds. Keiji becomes a more skilled fighter as he repeats the day, ultimately seeking a way to break the cycle and defeat the Mimics. The narrative has been adapted into various media, including a popular film titled Edge of Tomorrow.