Haibara-kun no Tsuyokute Seishun New Game

Natsuki Haibara is now a senior in college, after failing his debut and having miserable time in high school. He was on the verge of becoming a working adult, when he suddenly found himself transported back in time to seven years ago, just before starting high school! Natsuki, who had nothing but regrets for his high school life, gets a chance to "redo" everything. By making use of his past experiences, he succeeds in joining a group with the six most beautiful people in class, the top of the social caste! Even better, Youkari, the beautiful girl he once had a crush on, is also part of the group......!

A young man unaware of his own high-spec status gets the a second chance to enjoy his youth!

(Source: Firecross, translated)