JELEE is the credited original creator of the anime television series Jellyfish Can't Swim in the Night (Yoru no Kurage wa Oyogenai). Rather than a single individual, JELEE is a fictional anonymous artist group within the story that serves as the creative engine for the franchise. The series, produced by Doga Kobo for the studio's 50th anniversary, premiered in April 2024 and is set in Shibuya, Tokyo. The narrative follows four teenage girls who form the anonymous collective JELEE: an illustrator who had stopped drawing, a former idol who wishes to prove herself through singing, a self-proclaimed strongest VTuber, and a mysterious composer supporting her favorite person. Together, they collaborate to create and release music as an unnamed online artist. Within the series, the JELEE group consists of Mahiru Kozuki, known online as Yoru Umitsuki, who serves as the illustrator; Kano Yamanouchi, also known as Nonoka Tachibana, as the vocalist and lyricist; Kiui Watase, or Nox Ryugasaki, as the video editor and mixer; and Mei Takanashi, called Kimura-chan, as the composer.

As the creator credited for the original work, JELEE is officially listed for the anime television series. The anime was directed by Ryohei Takeshita, with series composition and screenplay by Yuki Yaku, original character designs by popman3580, and animation character designs by Junichiro Taniguchi. The music featured in the series as JELEE's songs was provided by real-world composer 40mP, with artwork by illustrator Hamunezuko, among other collaborators. An advance screening of the first two episodes took place in Tokyo in March 2024, and the series aired on Tokyo MX and other networks from April 7 to June 23, 2024. The opening theme is Irodori by KanoeRana, and the ending theme is Ichi-nichi wa 25-jikan by Anna Tsurushima. A manga adaptation illustrated by Niko Fujii began serialization on Kodansha's Magazine Pocket website in April 2024, and a light novel adaptation written by Yuki Yaku with illustrations by popman3580 was published by Shogakukan's Gagaga Bunko imprint. The series is licensed in North America and other regions by Sentai Filmworks.

Beyond the fictional representation within the anime, the name JELEE also refers to the in-story unit's musical output released as real-world products. A first mini album titled JELEE BOX was released in June 2024, followed by a second mini album, JELEE BAG, released in December 2025. The character of JELEE, as the vocalist and lyricist of the fictional group, has given interviews discussing the creative process behind these releases, including writing songs inspired by fan submissions and collaborating with manga authors for image songs. This layered presentation, where a fictional creator is credited for an original work that then generates real merchandise and music, establishes JELEE as a notable example of transmedia storytelling and the blurring lines between fictional narratives and real-world artist activities in the contemporary anime industry.