Zenshuu.

After graduating from high school, Natsuko Hirose starts her career as an animator. Her talent quickly flourishes, and she makes her debut as a director in no time. Her first anime becomes a massive hit, sparking a social phenomenon and earning her recognition as an up-and-coming genius director. Her next project is set to be a romantic comedy movie themed around first love! However, having never been in love herself, Natsuko struggles to understand the concept of first love, and as a result, she's unable to create the storyboard, causing the movie production to come to a standstill. One day, she passes out while working on her storyboard and wakes up in the world of her favorite childhood anime movie "A Tale of Perishing."

(Source: Crunchyroll)