Sparklers Under the Summer Sky
Koala's Diary (コアラ絵日記), the free YouTube anime based on Yuami's manga, has settled into a cozy quarterly rhythm since its October 2025 launch. Every three months: a new batch of episodes, a freshly drawn key visual, and a seasonal rearrangement of the same theme song. Japanese entertainment news site Comic Natalie reported that the summer installment, July vol.1, premieres July 2, 2026 at 8 PM JST on the show's official YouTube channel.
The fourth key visual, drawn by character designer Chiharu Hara (原千遥), shows Koala-san and the full crew (Kuma-chan, Karasu-san, Emu-san, and Harinezumi-san) holding sparklers under a summer night sky. It's the fourth in a series of seasonal key visuals, each depicting the same cast in a different setting.
For international viewers unfamiliar with the series: Koala's Diary is a gentle, low-key anime about a koala and animal friends going about their quiet daily lives. Voice actress Aya Uchida (Kotori Minami in Love Live! School Idol Project) plays every single character in the show, from the lead Koala-san to the entire supporting cast, all credited under her name.
A Theme Song That Changes With the Seasons
The show's theme, "Niji to" (Rainbow And) by Tokyo-based producer Punipuni Denki and multi-instrumentalist Kan Sano, gets a new arrangement each quarter. The summer version, titled "Niji to Yasashii Natsu ver.," swaps into a Latin groove. It releases digitally on July 3.
This is the fourth take on the same song. Punipuni Denki, whose production style blends jazz, bossa nova, and electronic textures, said the summer arrangement came together naturally. The producer noted that they and Kan Sano "wove in a really gentle Latin mood that fits Koala's Diary," and that during recording, they kept picturing Koala-chan and friends dancing along.
The seasonal-remix approach gives the show a quiet continuity. Same melody, different feel each quarter. It fits a series built entirely around small comforts and the rhythm of passing months.
Looking Ahead
Koala's Diary streams free on its official YouTube channel, with new episodes dropping in quarterly batches. The series is produced at studio MOTHER under director Yoshio Kado (加戸誉夫), with KADOKAWA handling production and music.
No English subtitles or international localization have been announced for the show. The source manga by Yuami is published by KADOKAWA in Japan, with no confirmed English-language release. For now, the YouTube episodes remain the only way to watch, though the show's visual warmth carries even without subtitles.
July vol.1 airs July 2 at 8 PM JST. The new theme song hits digital platforms the following day, July 3.