My ex-girlfriend is a magical girl junior?

In a world where magical girls are revered, Lin Che's skepticism is put to the test when he is reborn back to his junior year and gifted a transformation device called the Spark Lens. Forced to assume the persona of Starfrost, a mature and reliable senior, Lin Che navigates the uncharted territory of magical girl culture while keeping his true identity hidden. However, his situation becomes even more complicated when he discovers that his rescued magical girl is none other than his ex-girlfriend from his previous life, the daughter of his father's second wife. As Lin Che struggles to balance his two personas and protect his precarious social life, he must rely on his acting skills to maintain the façade and unravel the mysteries surrounding his rebirth.