Odoru Issei

Moments before victory, dark mage Kai Austin is betrayed and loses everything. His death becomes a reset, sending him five years into the past—to the day of the class assignment ceremony—with all of his magic intact. Armed with max-level dark magic and every memory of the future, Kai refuses to let history repeat itself. This time, he will protect Colette, stop the coming disasters before they begin, and destroy those who once betrayed him.

After hearing one of their friends having kissed, the girlfriend took matters into her own hands. Author's Twitter: https://twitter.com/odoru\_issei

In modern-day Shibuya, ninjas still exist. One of them is Enma, a master of fire techniques and the second son of the Iga Six Brothers. The brothers covertly protect the city by accepting requests for helping people and conducting spy missions. However, following the shocking event where the eldest brother, Shido, murders their father, Enma and his siblings become entangled in a series of incidents and battles against rival Koga ninjas. The central question remains: Can Enma reunite his family and continue safeguarding the streets of Shibuya?