Etsuya Mashima is a Japanese manga artist and original creator known for several comedy and slice-of-life manga series, many of which have been adapted into anime. Mashima’s name in Japanese is written as 真島悦也. Mashima is credited as the writer and illustrator for multiple manga titles, with a notable focus on the yonkoma, or four-panel comic strip format.

One of Mashima's most prominent works is the manga series Chitose Get You!! This series began serialization in 2002 in the magazine Manga Life Original, published by Takeshobo, and later moved to Manga Life MOMO. The series ran until 2014 and was collected into ten tankōbon volumes. Chitose Get You!! follows the comedic daily life of an eleven-year-old girl named Chitose Sakuraba and her romantic pursuit of a young man named Hiroshi Kashiwabara, much to the frustration of her teacher, Asako Fuji. The manga is a yonkoma, a format that typically structures its comedy around a tight, four-panel layout.

The popularity of Chitose Get You!! led to its adaptation into an anime television series. Produced by the animation studio Silver Link and directed by Takao Sano, the Chitose Get You!! anime premiered in Japan on July 1, 2012. The series consisted of 26 episodes, each with a runtime of approximately three minutes. The anime was broadcast on networks including the Kyoto Broadcasting System and AT-X. Mashima is officially credited as the original creator for this anime adaptation.

Furthermore, Mashima's work on Chitose Get You!! also served as the basis for a separate original animation video, or OAV, titled Asako Get You!! Released in 2013, these two OAV episodes focused on the high school days of the character Asako Fuji, a teacher in the main series. Mashima is listed as the original creator for Asako Get You!! as well, with the OAV being based on bonus chapters from the Chitose Get You!! manga.

Beyond the Chitose Get You!! franchise, Mashima has authored several other manga series. Another notable work is Koi Neko, which was published by Shogakukan. This series was released in multiple tankōbon volumes starting in 2005 and received an official licensed translation for publication in Taiwan. Mashima is also the creator of the manga Hiyomama and Mirai no Attaka Cup. In 2013, Mashima launched a new series titled Zombie-chan in Shogakukan's Sunday GX magazine. This series was described as a dark comedy, featuring the idle conversations of zombie girls dressed as maids, which marked a stylistic departure from his more grounded slice-of-life works. Throughout these projects, Mashima consistently fulfills the dual roles of writer and artist, handling both the story and the illustrations for his manga. The recurring use of the yonkoma format and a focus on character-driven comedy are identifiable elements of his artistic identity.