Diary of a Female Lead: Shujinkou Nikki manga volume 1 features story and art by Yuu Yoshinaga.

Tsujimura Aoi wouldn't consider herself a main character by any means. Meek and insecure, she's constantly alone, unlike her athletic older brother, Itsuki, or her mother, a famous shojo mangaka. Aoi doesn't need to be the heroine, though—all she wants is a true friend. But Itsuki disagrees, and when he brings home Aoi's effortlessly cool classmate Mizusawa Sena, the two concoct a plan to teach Aoi all about love, using shojo manga as their guide. Can this drab side character become an unparalleled female lead by falling for the perfect guy?