I Was Mistaken as a Genius Mage in a Game - Chapter 86

Three years ago, in the land of Reinbulk, a Legendary Hero was summoned in the Kindom of Leezalion and he succeeded in repelling the Demon King. Now, five students are summoned back into Reinbulk by the Kingdom of Luxeria to fight against the Demon King and the demon army. Unlike the other heroes, Yashiro Yuu has no magical affinity and the Luxeria Kingdom has no intention on acknowledging his existence or returning him to his world.

Alexander Gray, a fifteen-year-old teenager on the verge of his awakening and subsequent entry into the Hunters Academy is one day taken away in a cosmic mana wave that passes through Earth’s solar system during a school trip from Earth to Mars. A wave that kills a person once exposed to it. Luckily, the displacement wave placed him close to their destination where he was found, alive and well to the disbelieve of everybody. Unbeknownst to him at the time, the cosmic mana wave had awakened a gift within him that would propel him to the ranks of hero hunter and beyond, granting him the strength to lead humanity in their effort to determine the cause of their universe changing and its implications. ............. “For some reason, I can’t level up.” Alex began to feel frustrated as he was stuck at Class F, the lowest rank a hunter could have after awakening, despite his momentum when he first awakened. Even with his awakened talents and the benefits he received from the ’accident’ that should have killed him, he now finds himself stuck and unable to level up as mana does not work on him like everyone else. Follow Alexander Gray as he discovers his abilities and learns about himself in a chaotic universe and beyond.

A chance to change, to challenge destiny, making dreams a reality, and live a legend! A regular man gains a system that allows him to turn into a fish!

- Description from Novelupdates

When I was 15-years-old, during the year that I graduated from middle school, my father told me this.