Tensei Shitara BL Manga no Sekai Datta Ken

After getting stabbed on the bus, the manga artist Tetsuo Tanaka finds that he has been reincarnated...into the BL manga he created?! Although he quickly runs into the sexually adventurous love interest Takumi, Tetsuo has unfortunately been reincarnated as Atsushi, the promiscuous rival to the canon seme. Will he be able to rewrite the plot and find a happy ending with the man of his dreams? Even if he can't, there's sure to be plenty of "fun" along the way!

(Source: Animate International)