
Guide
Irida Yanagi-bayashi is a natural willow forest situated near the upstream area of the Akatetsu Bridge, along the lower reaches of the Shimanto River in Shimanto City, Kochi Prefecture. The most striking feature of this location is the seasonal display of Manjushage (Red Spider Lilies) that bloom across the forest floor. From mid to late September, the vibrant red flowers peek through the soft green willow leaves, creating a mystical landscape that looks as if a brilliant red carpet has been laid out beneath the sunlight filtering through the canopy.
This area has long coexisted with the natural environment of the Shimanto River. The preservation of this natural willow forest makes it a symbol of the local landscape. The blooming of the Manjushage is a significant seasonal event for the community, marking a beautiful cycle of nature that locals and visitors alike cherish.

The absolute highlight is the blooming of the Manjushage between mid and late September. The contrast between the soft light filtering through the willow leaves and the brilliant red of the flowers is a dream for photographers and nature lovers. Within this approximately 1km stretch of natural forest, the sight of the landscape turning entirely red is a rare and precious spectacle that can only be witnessed during this specific time of year.
The most notable time to visit is during the Manjushage season in mid-to-late September. During the bright daylight hours, the sunlight filtering through the trees makes the colors appear exceptionally vivid. Conversely, as the sun begins to set, the forest takes on a more serene and mystical atmosphere. We highly recommend checking the local blooming status before your visit to ensure the best experience.
Visitors can enjoy a peaceful stroll through the forest to feel the changing seasons. Within the unique atmosphere created by the natural willow forest, you can spend a quiet moment admiring the beautiful flowers. It is an ideal place to engage all your senses and capture the seasonal colors with a camera.
The surrounding area is dotted with spots where you can experience beautiful nature and local culture. As part of the scenic Shimanto River area, it is a perfect destination for a scenic drive or a nature walk. You can easily combine a visit here with other sightseeing routes in Kochi Prefecture, such as botanical gardens or historic townscapes.
Since you will be walking through a natural forest, comfortable clothing and sturdy walking shoes are highly recommended. Please keep the following in mind: