My ex-girlfriend is a magical girl junior?

Are there men in this world who would refuse a Spark Lens? Lin Che, at least, thought not. So, reborn back to the summer of his junior year, he used a transformation device called the Spark Lens, a gift from a mysterious system, to transform into a magical girl. To avoid revealing his true identity, he was forced to assume the persona of Starfrost, knowing nothing about magical girls, and had to play the role of a mature and reliable senior, guiding his juniors as they grew. To make matters worse, he discovered that the daughter of his father's second wife was not only the magical girl he had just rescued, but also his ex-girlfriend from his previous life? "Is it too late to cancel this rebirth package?" And so, this unlucky guy, constantly switching between two identities, began to use his acting skills to protect his two personas—and his precarious social life.