Despite his lack of success in writing competitions, Yuu Nagami remains determined to become a successful light novel author. However, when his sister Suzuka, writing under the pen name Chikai Towano, dominates the latest competition, Yuu is shocked to discover her true identity. Suzuka begs him to take her place and continue pretending to be Chikai Towano until he is able to publish his own book. Yuu agrees, but only on the condition that he is able to use this as an opportunity to improve his writing skills and network with fellow authors. Yuu sets out on a journey under his sister's name, meeting new acquaintances and improving his craft along the way.