Oreki Houtarou is a minimalistic high school boy. One day, he joins the Classic Literature Club at his elder sister’s request. There he meets Chitanda Eru, Fukube Satoshi, and Ibara Mayaka. Chitanda is a calm beautiful girl but she turns into an embodiment of curiosity once she says, “I’m curious.” Fukube is a smiling boy with a fantastic memory who calls himself a database. Ibara is a short girl and is strict with others and herself. They begin to investigate a case that occurred 45 years ago. Hints of the mystery are buried in an old collection of works of the former members of Classics Club. The collection is titled “Hyouka.”

Kyuta, a boy living in Shibuya, and Kumatetsu, a lonesome beast from Jutengai, an imaginary world. One day, Kyuta forays into the imaginary world and, as he’s looking for his way back, meets Kumatetsu who becomes his spirit guide. That encounter leads them to many adventures.