Yuusha-sama, Shimekiri desu!

Manga artist goes to another world! Kaede Toudou, a mid-career manga artist, was summoned to another world three days before the deadline for her manuscript!? She must defeat the Demon King in order to return to the real world. She receives the legendary katana as a template, and in order to complete the manuscript, she goes at full speed and defeats the demon king! (Source: Houbunsha, translated)