Synopsis: Gakureki Musou Academia ~F-Rank Hokyuu Gakari ga Saikyou Rejendo Madoushi ni Tensei~

"With a score like yours, you don't even deserve to live." Welcome to a magical world entirely ruled by academic prestige. Here, if your test scores are low, your very humanity is stripped away. Eito, a low-tier outcast working as a miserable supply clerk, thought he had seen the absolute rock bottom of this ruthless society. But his world truly shatters when his beloved younger sister is brutally murdered by a mysterious monster known only as the "Unknown." Losing everything in a flash of despair, Eito expects the end—only to awaken twenty years in the past, standing right in the middle of the Academia’s entrance exam hall. Gifted with a legendary, ultra-high-spec skill set in his second life, the boy once mocked as the academy’s weakest link is back. Armed with flawless foresight and unmatched power, Eito is ready to completely smash the academic caste system to pieces and seize the top spot by absolute force! This time, he will protect his sister, uncover the truth, and rewrite the world. The ultimate academic-caste battle fantasy begins now! _Source: Mechacomic, translated_