I'd say it's likely a case of misinterpretation. Maybe there are similarities that you overlooked or differences that you focused on too much, leading to the conclusion that it's not the intended manga.
Sister Lover was a Japanese manga about the love story between the protagonist and his half-sister. The ending of the manga had not been decided yet because the storyline had not yet ended. Some readers and the media speculated that the manga might usher in a happy ending where the protagonist and his half-sister could find their own happiness. However, these speculations were just speculations. The details of the ending of the manga would only be known after the work was completed.
Cosmetic play lover manga often incorporates elements like trendy makeup looks, challenges, and self-discovery through beauty. The art style might be colorful and eye-catching to draw in readers. Also, it could have elements of romance or friendship tied to the world of cosmetics.