Theme Pavilion "NEKKO"

Theme Pavilion “NEKKO” is the core exhibit run directly by the GREEN×EXPO Association; the official English site also calls it the Themed Pavilion. Its concept is “All life is connected, with plants at the heart.” Plants make up more than 80% of the Earth’s biomass, and the pavilion uses art and entertainment grounded in the latest science to show their hidden abilities and their ties with other life, encouraging action based on Nature-based Solutions (NbS).

The nickname Nekko (“roots”) was chosen from a public call held June 5–26, 2026, which drew 3,611 entries in total for three facilities (the Theme Pavilion, the Horticultural Pavilion and the Indoor Exhibition Facility), and was announced on September 15. It comes from the image of plant roots in the concept, and also from the way the building applies the logic of plant forms and structures to architecture.

Highlights and exhibits

The exhibition has six zones, as announced on September 15, 2026 and described on the official site:

• Prologue: a concept film welcomes visitors and introduces the themes ahead.
• ZONE 1 A World Under the Forest: the underground network of plant roots and fungal hyphae, shown with projection mapping, sound, light and real specimens. The real roots of the “Miracle Pine” of Rikuzentakata, Iwate, which survived the 2011 tsunami, are on loan and built into the show.
• ZONE 2 The Forest of Hidden Worlds: based on the idea of Umwelt (the world as each organism perceives it), it visualizes the signals plants send through scent and color. A huge indoor planting area brings together plants from Central American rainforest to Japanese laurel forest, including banyan trees and laurel forest over 5 m tall. Parasitic plants that cannot be brought from the wild, such as Rafflesia, appear as detailed life-size models made with 3D scanning. An “Umwelt Theater” shows how plants sense time and the world around them.
• ZONE 3 Discoveries in the Forest: three areas where visitors see and touch familiar plants that face threats such as extinction; for example, the ginkgo is common on city streets, but wild ginkgo is endangered. Outdoors, an area named Mirai ni nokoshitai shokubutsuen (“a botanical garden to pass on to the future”) hides QR codes among the plantings so visitors can build an illustrated plant guide, stamp-rally style.
• ZONE 4 Our Connections to Plants: visitors walk through the “Tunnel of Abundance” inside a giant book, tracing what plants have given people, from food, clothing and shelter to medicine and comfort. The same book shows how close we are to the planetary boundaries and introduces nature-based solutions. The zone ends with the “Tree of Hope,” shown on a large screen and made from photos of plants that visitors grew from Seed Paper®.
• Epilogue: blue-flowered mizuaoi, an endangered plant that bloomed across tsunami-scarred coasts, and an ancient lotus that grew from 2,000-year-old seeds found at a dig in Chiba City lead to a final message for visitors.

Seed Paper® and the “Tree of Hope”

Visitors receive Seed Paper®, recycled paper with plant seeds inside. Photos of the plants they grow can be posted on a dedicated site, where they become part of the “Tree of Hope”; the more photos, the more the tree grows. Posting opened on July 31, 2026, and the photos will be shown at the pavilion after the Expo opens. The paper is made from shredded paper collected from Expo exhibitors, with seeds added by washi papermakers, including Nishijima washi craftspeople in Minobu, Yamanashi, and printing and assembly carried out by people with disabilities.

Building and design

Kengo Kuma & Associates is supervising the design of a large timber building made of CLT (cross-laminated timber). The firm’s design director explains that the starting point was “architecture like a plant”: inspired by the traditional technique of the Kesen carpenters, whose roof beams become smaller and lighter toward the top, the structure spreads out like a tree from trunk to branches. Foundations are kept to a minimum so the soil remains continuous, the wall-columns follow the prevailing south-to-north wind, and planting on the south side cools the incoming air.

Construction is led by Obayashi Corporation’s site office. With no grid lines and CLT panels set at irregular angles throughout, the team checked the assembly with 3D-printed models and aims for an accuracy of ±1 mm.

About the organizer

The Theme Pavilion is one of three facilities run directly by the Association, along with the Horticultural Pavilion “IROHA-GARDEN” and the Indoor Exhibition Facility “HANAMEGURI.” The exhibition director is Ou Sugiyama of Shinryoiki Inc., who served as Chief Planning Director of the Signature Pavilion “INOCHI no Akashi” at Expo 2025 Osaka, Kansai, Japan. NHK Global Media Services plans and produces the exhibits on the bond between plants and people, and Nippon Life Insurance Company, a Platinum Partner, provides ZONE 3 and the outdoor botanical garden area.

Timeline

• October 1, 2024: Exhibition director Ou Sugiyama joins a talk session at the first exhibitor announcement (Association press release)
• March 19, 2025: The Association outlines the exhibition, including the “Miracle Pine” roots and the underground world of plants and fungi
• March 19, 2026: The pavilion’s official website opens; Nippon Life is named Platinum Partner for the Theme Pavilion project
• April 13, 2026: “Inside Heroes,” a series on the people behind the pavilion, begins
• May 2026: Seed Paper® is handed out at the Yokohama Flower & Garden Festival 2026, then at other events
• June 5–26, 2026: Public call for nicknames for three facilities
• July 16, 2026: Recruitment of pavilion operations staff begins (closed August 31)
• July 31, 2026: Photo posting for the “Tree of Hope” project opens
• September 15, 2026: The nickname “NEKKO,” the six-zone layout and Nippon Life’s ZONE 3 and outdoor content are announced
• September 29, 2026: The official website is renewed with detailed zone pages

On social media

The Association announced the nickname (September 15) and the website renewal (September 29) on its official channels. On X (formerly Twitter), many posts shared the nickname news, with attention on the six-zone layout and the “Miracle Pine” roots (as of October 2026).

Before you go

• Location: On the Association’s venue map (June 1, 2026 edition) it is on the eastern side of the northern area, east of the Kids Village, near the Indoor Exhibition Facility, with the Horticultural Pavilion further southeast.
• Reservations: The Association’s FAQ says the reservation method for the Theme Pavilion is still under consideration (as of October 2026). Facilities using same-day viewing reservations have not been announced.
• Admission: No viewing fee beyond the Expo ticket, except for merchandise (Association FAQ).
• Before the Expo: Seed Paper® will be handed out on October 10–12, 2026 at the GREEN×EXPO 2027 booths at the Osaka Urban Greening Fair 2026, the EXPO2025 Futures Tour in Tokyo and “1st Anniversary EXPO 2025” in Osaka, to those who answer a survey or quiz, while supplies last (official site).
• Not yet announced: Visit length, activities for children and accessibility details.

Sources

• Expo Association: Themed Pavilion (checked 2026-10-04)
• Theme Pavilion “NEKKO” official site (English) (checked 2026-10-04)
• Theme Pavilion “NEKKO”: About the ZONES (checked 2026-10-04)
• Expo Association press release on the nicknames and zone layout, September 15, 2026 (Japanese) (checked 2026-10-04)
• Expo Association: Results of the nickname call, September 30, 2026 (Japanese) (checked 2026-10-04)
• Expo Association: Website renewal notice, September 29, 2026 (Japanese) (checked 2026-10-04)
• Inside Heroes vol.1: Ou Sugiyama (Japanese) (checked 2026-10-04)
• Inside Heroes vol.2: Kai Araki, Kengo Kuma & Associates (Japanese) (checked 2026-10-04)
• Inside Heroes vol.3: Akihiko Uchida, NHK Global Media Services (Japanese) (checked 2026-10-04)
• Inside Heroes vol.4: Shutaro Nakamura, Theme Pavilion site office (Japanese) (checked 2026-10-04)
• Inside Heroes vol.5: Setsuko Noguchi, SOUP (Japanese) (checked 2026-10-04)
• Inside Heroes vol.6: Shinji Kasai, Yamaju Paper (Japanese) (checked 2026-10-04)
• Theme Pavilion news (Seed Paper® distribution and photo posting, Japanese) (checked 2026-10-04)
• Expo Association: Theme Pavilion staff recruitment, July 16, 2026 (Japanese) (checked 2026-10-04)
• Expo Association press release, October 1, 2024 (Japanese) (checked 2026-10-04)
• Expo Association press release, March 19, 2025 (corrected March 21, Japanese) (checked 2026-10-04)
• Expo Association press release, March 19, 2026 (Japanese) (checked 2026-10-04)
• Expo Association FAQ (Japanese) (checked 2026-10-04)
• Expo Association: Village and themed commercial outlets, venue map (Japanese) (checked 2026-10-04)

*Exhibit details and highlights will be updated as official announcements are made.