The official website for the web anime adaptation of Yuami’s Koala E Nikki (Koala’s Diary) manga revealed its main promotional video, full cast, and staff on Monday, September 29, 2025. The highly anticipated series is set to premiere on October 2, 2025, on its official YouTube channel.
Unveiling the Voice Behind Koala and More
Veteran voice actress Aya Uchida will lead the cast, not only lending her voice to the titular Koala but also portraying several other key characters. Uchida is confirmed to voice Karasu-san (Crow-san), Emu-san, and Harinezumi-san (Hedgehog-san), alongside other characters in the heartwarming slice-of-life series.
Key Production Team Bringing the Diary to Life
The web anime is being directed by Takao Kato at Studio Mother. Kato has a notable directorial history, including works like As a Reincarnated Aristocrat, I’ll Use My Appraisal Skill and To Love-Ru. Chiharu Hara, known for her key animation work on titles such as More Than a Married Couple, But Not Lovers, is handling the character designs for Koala’s Diary.
Further strengthening the production team, the newly announced staff members include:
- Art Director: Chiaki Tsujimoto
- Color Design: Mitsuko Sekimoto
- Compositing Director of Photography: Kōji Yamakoshi
- Editing: Kaori Umewaki
- Sound Director: Takayuki Yamaguchi
- Sound Effects: Yui Andō
- Sound Production: HALF H·P STUDIO
- Music: Atsushi Umebori and Slavomir Stanislaw Kowalewski
- Music Production: Kadokawa
“Niji to” Sets the Tone as Theme Song
The main promotional video offers a preview of the anime’s theme song, titled “Niji to” (With a Rainbow). This track is performed by Punipuni Denki featuring Kan Sano, promising an enchanting auditory experience to accompany Koala’s daily musings.
Premiere Details and Manga Background
The Koala’s Diary web anime is scheduled to begin streaming on October 2, 2025, at 8:00 p.m. JST, exclusively on the anime’s official YouTube channel. New episodes will be released every Thursday.
The anime is based on Yuami’s Koala E Nikki manga, which originally began serialization on the author’s X (formerly Twitter) account on June 11, 2021. Kadokawa Corporation has been publishing the compiled book volumes, with the first volume released in 2022 and the fourth volume on February 14, 2025. The heartwarming story revolves around Koala, who meticulously records their daily life, embracing both good and bad, happy and sad moments as precious.
