Bullied Boy Awakens SSS-Rank Summon

Cleaner Grace works ten years to buy her son Ethan an awakening potion—but nobles steal and destroy it. He drinks the leftovers, awakening an SSS-rank summoner gift. The crystal can't read his limit, so he's judged F-rank. To prove himself and end his mother's humiliation, he enters the Federation trials. Can this "trash" boy break the class rules?