is a Japanese manga written and illustrated by Takuma Morishige. The series follows a girl named Rumi Yokoi who is constantly distracted by her neighboring classmate, Toshinari Seki, as he indulges in elaborate hobbies and somehow never gets caught in the process. Originally published as a one-shot in 2010, it started serialization in the November 2010 issue of Media Factory's Comic Flapper magazine. Vertical publishes the manga in North America. An original video animation by Shin-Ei Animation was released bundled with the limited edition of the manga's fifth volume on January 4, 2014, and a 21-episode anime adaptation aired in Japan between January and May 2014. A spin-off manga serialized from July 2020 to May 2023.
Written and illustrated by Takuma Morishige, the manga began as a one-shot published in the August 2010 issue of Media Factory's Comic Flapper magazine, and later started serialization in the magazine's November 2010 issue. The first tankà Âbon volume was published on April 23, 2011 and the tenth was released in March 2017. Vertical licensed the manga for North American publication under the title My Neighbor Seki, and has been releasing volumes since January 2015.
A spin-off series titled My Neighbor Seki-kun Junior launched in the July 4, 2020, issue of Monthly Comic Flapper. The spin-off ended in the May 2, 2023, issue of Monthly Comic Flapper. The spin-off's chapters were collected into three tankà Âbon volumes from June 23, 2021, to June 22, 2023.
A 21-episode anime directed by Yà «ji Mutoh and produced by Shin-Ei Animation, aired in Japan between January 5 and May 25, 2014, and was simulcast by Crunchyroll under the title Tonari no Seki-kun: The Master of Killing Time. The fifth manga volume was released simultaneously on January 4, 2014, with a limited edition, bundled with an original animation DVD containing two additional episodes. The series was released on DVD in two parts on May 28, 2014, with a bonus episode on each disc. The opening theme is by Kana Hanazawa, and the ending theme is "Set Them Free" by Akira Jimbo. The music in the series is composed by Akifumi Tada. The drama CD for the anime was released on January 22, 2014, by King Records.
The series was adapted into a live-action show where it was paired with another live-action adaptation titled Rumi's Phenomenon. Both programs involve a main character named Rumi. It premiered on MBS and TBS on July 27, 2015 as and ran for eight episodes. Morishige said "I feel a sense of odd destiny that the heroines' names are coincidentally the same."
Over 3 million copies of the manga have been sold as of July 2014. The manga was one of the works nominated in the fifth Manga Taishà  awards in 2012. My Neighbor Seki was listed on YALSA's 2016 list of Great Graphic Novels for Teens.
Rebecca Silverman of Anime News Network gave the first volume of the manga an overall grade of C+. Karen Mead of Japanator liked that the anime put the detail into Seki's projects rather than the characters, and that while the show could have worked as a three- to four-minute short, that it gets stretched to eight minutes with opening and ending themes gives it a chance to build atmosphere and tension. Richard Eisenbeis of Kotaku called it "the most basic, yet perhaps most entertaining, anime of the season."