The Law of Immutability 

Woo-Ri Nam has always been the golden boy—wealthy, carefree, and untouchably lucky. But on the leap day of 2028, his 7th real birthday, everything changes. A seemingly harmless reunion with an old classmate, Su-Bin Shin, ends in a brutal murder. And then, inexplicably, Woo-Ri wakes up back in high school, right beside Su-Bin who has no idea that he just killed his deskmate. Trapped in a deadly time loop where almost every timeline ends with his death at Su-Bin’s hands, Woo-Ri becomes desperate to escape his fate. After multiple resets, Woo-Ri finally comes to the conclusion that the only path to survival may be ensuring Su-Bin’s happiness. With just one life left, Woo-Ri sets out to give Su-Bin the happiest life possible. (Source: WEBTOON)