Title: I never thought I made a harem by making a manga
Synopsis:
"As a child, Kenji Yoshikawa did everything by himself and dropped it once he was bored. But his family is full of mystery, especially his father, a retired mangaka. After finding out the secret behind his father's actions, he decided to pursue becoming a mangaka. After this, surprisingly, he somehow managed to get into a harem due to his manga works."
Link: https://www.webnovel.com/book/i-never-thought-i-made-a-harem-by-making-a-manga_18080645005182205