A collection of short stories set after the K - Return of Kings anime posted on its official website.

A novel adaptation of K, SIDE:RED tells the story of how the current red clan was created, the background story of Kushina Anna, and details... more>> of Kamamoto Rikio, Yata Misaki and Fushimi Saruhiko joining the red clan and their time together as a clan. <<less

A novelization of K which tells the story of how Misaki Yata and Saruhiko Fushimi met and parted ways. There are three parts: "Meeting," "Getting... more>> Along," and "Betraying." <<less

A collection of side stories included with the blu-ray limited editions of the K - Return of Kings anime.... more>>

- BD1 「潜伏と再開」 (On Lying in Hiding and Reunions) by Miyazawa Tatsuki
- BD2 「剣、二振り」 (Swords in a Pair) by Suzuki Suzu
- BD3 「テンペルホーフ１９４５」 (Tempelhof 1945) by Takahashi Yashichirou
- BD4 「クリスマス・キャロル」 (Christmas Carol) by Furuhashi Hideyuki
- BD5 「昴／長男と、その親友」 (The Pleiades & The Eldest Son and His Best Friend) by Kabei Yukako
- BD6 「デスパレート・ゲーム」 (A Desperate Game) by Raikaku Rei
- BD7 「ある少年の進路探し」 (A Certain Boy’s Search for his Future Path) by Azano Kouhei <<less

A novelization of K, K SIDE:Black & White takes place in a love hotel that Yashiro, Neko, and Kuroh hide in after the events of... more>> the K anime episode 8. The novel features them talking to one another and remembering their pasts. <<less

A collection of 4 chapters set before the K - Return of Kings anime.... more>>

– Blue chapter 「眼鏡屋別サイド」 (Optician’s, Another Side) by Miyazawa Tatsuki

– Silver chapter 「お風呂ネコトラブル」 (Neko Bathtime Trouble) by Raikaku Rei

– Green chapter 「”JUNGLE”」 (“Jungle”) by Takahashi Yashichirou

– Red chapter 「呼び名のその後」 (Aftermath of the Nickname) by Suzuki Suzu <<less

A novel adaptation of K, focused on the history of the blue clan and the events which led to Munakata Reisi's appointment as the current... more>> blue king. <<less

- 「スウィート・バレンタイ」 (Sweet Valentine) by Furuhashi Hideyuki
- 「おひなさまの着物」 (A Doll’s Kimono) by Raikaku Rei
- 「お花見」 (Flower Gazing) by Suzuki Suzu
- 「砂のお城」 (Sand... more>> Castle) by Kabei Yukako
- 「もしかしたらあったかもしれないハロウインナイト」 (A Halloween That Might Have Happened) by Miyazawa Tatsuki
- 「クリスマス１９４４」 (Christmas 1944) by Takahashi Yashichirou
- 「初詣」 (The First Shrine Visit of New Year) by Azano Kouhei <<less