Tekkarian

Gakuto Watari was a highly educated elite, but his extreme arrogance about his academic background led to his total defeat in the job hunting wars, turning him into a toxic NEET who did nothing but lurk on internet message boards. Suddenly, he is abducted by a giant alien known as a 'Tekkarian' Under the pretense of 'rehabilitation,' he is forced into manual labor in a mysterious underground facility alongside other middle-aged men living with their parents. Naturally, his high-spec pride refuses to tolerate such tyranny and oppression. With a brain packed with extensive knowledge, he prepares to shut them down with logic and debate—or at least he would, if he weren't too terrified and overwhelmed to even squeeze out the courage...