Following in his missing sister Miyuki's footsteps, high school freshman Shindou Satoru joins the school's archery club, which, at the time, has only one member - second-year student Kaname Yumiko.
After picking up a bow for the first time, Satoru suddenly finds himself in a strange world, where he is attacked by bow-wielding spirits. To Satoru's surprise, Yumiko appears by his side to protect him, but in the end is defeated by the spirits. At the mercy of his enemies, Satoru is saved by a seemingly non-hostile spirit named Hannya (a Buddhist word for wisdom).
Returning to his world, Satoru learns about the Kyudoshi's (Archer's) obligation to battle the spirits. Being further told by Yumiko that his sister Miyuki was a Kyudoshi as well, and went missing while battling a spirit bearing a strong resemblance to Hannya, Satoru decides to accept his fate - to take up the battle and hopefully find his sister.