Marimo Festival 2026
For three days every October 8-10, Ainu elders at Lake Akan hold sacred kamuinomi prayers, a torchlit lakeside parade, and a ceremonial send-off of the marimo algae balls into the water - a tradition dating to 1950 that protects the lake's famous round colonies, a Japanese Special Natural Monument since 1952.
When · Where
- When
- 2026/10/08 10:00 – 2026/10/10
- Where
- Akanko Ainu Kotan and the Lake Akan lakeside park (Kohan-Enchi), Kushiro（4-7-84 Akancho Akankoonsen, Kushiro, Hokkaido 085-0467）
- City
- Across Japan
- Getting there
- Lake Akan has no train station; the nearest hub is JR Kushiro Station (reached via the Super Ozora limited express from Sapporo, about 4 hours), from which Akan Bus's 'Akan Line' runs to the Akanko Onsen bus centre in roughly 2 hours. From Kushiro Airport, a direct airport bus takes about 60 minutes; Memanbetsu Airport, somewhat further, is another common gateway. The Ainu Kotan and lakeside park venues are within a short walk of each other in Akanko Onsen town.
- Price
- Free
- Organizer
- Akan Tourism Association Community Development Organization & Lake Akan Marimo Conservation Society (阿寒観光協会まちづくり推進機構・阿寒湖のマリモ保護会)
Good to know for visitors
- Getting there
- Lake Akan has no train station; the nearest hub is JR Kushiro Station (reached via the Super Ozora limited express from Sapporo, about 4 hours), from which Akan Bus's 'Akan Line' runs to the Akanko Onsen bus centre in roughly 2 hours. From Kushiro Airport, a direct airport bus takes about 60 minutes; Memanbetsu Airport, somewhat further, is another common gateway. The Ainu Kotan and lakeside park venues are within a short walk of each other in Akanko Onsen town. Open directions in Google Maps ↗
- Booking & entry
- Free to attend — details on the official page (button above).
- Language
- Mostly in Japanese — a translation app on your phone helps.
- Good for
- culture seekers
Highlights
- On the final morning, Ainu elders perform the kamuinomi prayer at the Ainu Kotan before carrying the marimo in procession down to the lakeside park for the marimo-okuri - a ceremonial return of the algae balls to Lake Akan by dugout canoe
- On the second night, a torchlit parade (taimatsu gyoshin) winds from the lakeside park to the Ainu Kotan, followed by a marimo-mukae welcoming rite and a competition of traditional Ainu dances at the Ainu Theatre
- Marimo form dense, free-floating spheres of the alga Aegagropila linnaei; Lake Akan's colonies were designated a national Natural Monument in 1921 and upgraded to Special Natural Monument status in 1952, and the festival has protected them every year since 1950
Background & story
The Marimo Festival began in 1950 after wartime and postwar over-collection had pushed Lake Akan's marimo colonies to the brink, combining Ainu ceremony with a conservation message. Marimo - dense, free-floating spheres formed by the alga Aegagropila linnaei - grow to their famously large, round form at Lake Akan through a combination of wave action and light; the lake's marimo habitat was designated a national Natural Monument in 1921 and the marimo itself was elevated to Special Natural Monument status in 1952.
Good to know
Dress warmly - Hokkaido evenings in October are cold, especially for the lakeside torch parade. The final morning's kamuinomi and marimo-okuri are the most moving parts of the festival and free to observe, so plan to stay through day three rather than just catching the opening evening.