Koten-bu series (〈古典部〉シリーズ "Koten-bu" shirīzu) or Classic Literature Club series is a novel series written by Honobu Yonezawa and serialized in Kadokawa Shoten. Currently, the series consists of 6 volumes.
Also one special volume named Honobu Yonezawa and the Classics Club was published. It's dedicated to the process of Koten-bu series creation and also includes one new short story about Houtarou Oreki.
"Everyone wants to live their high school life to make many good memories". This high school student motto doesn't interest Houtarou Oreki. He doesn't want to "waste" his energy on relationships, sports or some other activity. Instead he wants is to "save his energy" by all means. Because of it he has no interest whatsoever in joining any clubs upon entering Kamiyama High School.
But his life changes when he receives a letter from his older sister Tomoe in which she wants him to enter the Kamiyama High School Classic Literature Club (Classics Club), which was in danger of getting abolished as all previous members have graduated. Being afraid to refuse his sister Hōtarō does so, thinking that this won't change anything in his life - he expected to be single club member. But he finds out that he was wrong - when he enters the clubroom, he sees a beautiful girl, standing near the windows and looking to outside. She notices Hōtarō and introduces herself. She is Eru Chitanda from 1-A class, and a member of Classics Club. After some time, his old friends Satoshi Fukube and Mayaka Ibara join to club as well. The newly reformed Classics Club find themselves involved in all sorts of mystery-solving escapades.
Each volume (except vol. 6 and Honobu Yonezawa and the Classics Club) was given different Japanese and English title. In this article translated Japanese title used as main.
English: You can't escape / The niece of time
Volume 1 of the series. "Energy conservation" advocate Houtarou Oreki enters the Classics Club together with girl named Eru Chitanda who forces him to solve a mystery hidden in the anthology "Hyouka" to find out the truth about events which took place 33 years ago.
Japanese: 愚者のエンドロール (Gusha no Endo Rōru)
English: Why didn't she ask EBA?
Volume 2 of the series. Last third of August, spring break. Classics Club's members were asked to choose appropriate ending for the class 2-F's uncompleted mystery film from variants presented by three amateur detectives from the film production team.
Japanese: クドリャフカの順番 (Kudoryafuka no Junban)
English: Welcome to KANYA FESTA!
Volume 3 of the series. Plot evolves around events occurring during the three-day Kamyama High School Cultural Festival nicknamed "Kanya Festival". Classics Club is trying to solve "Juumonji case", a case of serial theft in school during festival.
Japanese: 遠まわりする雛 (Tōmawari Suru Hina)
English: Little birds can remember
Volume 4 of the series, collection of new short stories. Following three previous stories, plot evolves around four Classics Club's members from time they enrolled to the high school to spring break of the following year.
Japanese: ふたりの距離の概算 (Futari no Kyori no Gaisan) English: It walks by past
Volume 5 of the series. Classics Club members become second-year students. While running the 20 km June marathon named "Hoshigaya Cup", which is also a deadline for joining clubs, Houtarou tries out to find a reason why first-year student Tomoko Oohinata who was eager to join Classics Club at first, changed her heart and announced her withdrawal.
Japanese: いまさら翼といわれても (Imasara Tsubasa to Iwaretemo)
Kadokawa Shoten, November 30, 2016. ISBN 978-4-04-104761-3
Volume 6 of the series. Collection of short stories. Before her solo performance at Choral Festival Eru suddenly disappears. Houtarou is forced to use various hints to deduce her whereabouts. Also it includes five other stories.
There is an ongoing manga adaptation illustrated by Task Ohna.
The anime adaptation Hyouka by Kyoto Animation covers Vols. 1-4 of the Kotenbu series series, as well as a few short stories (Is The Mountain Range Sunny?, later included in Vol. 6). At the end of each episode the subtitle of the volume that the story arc is from is displayed.