Takaga Shishaku Chakunan ni Kouki na Hitotachi ga Guigui Kite Komaru @comic

The Royal Academy of the Ezelbite Kingdom, the largest school in the kingdom, is home to princes, duchesses, sons of powerful men, and other people with prestigious titles. At first glance, Rey appears to be a fast-paced young man who cares little about success or social mobility. But in fact he is the "strongest NPC" with the blessing of a powerful spirit and charisma!

He attracts the attention of the prince, the prince's fiancee, saints, and others, and even finds himself in a harem! Rei meets various people, leading to his destiny changing often. unaware that this world itself is an RPG "Real Fantasy". A boy with no desire for success and no self-awareness changes the world!

(Source: TO Books, translated)