The Sumitomo Pavilion at the 2025 Japan International Exposition (Osaka-Kansai Expo) is a pavilion where visitors can experience a grand "story of life" set in the "UNKNOWN FOREST." With lanterns in hand, children and adults alike can freely wander through the forest and experience the interconnectedness of life that is usually unseen. In response to the movements of visitors, light and mist change, and the "story of life" in nature emerges in the forest, depicting trees conversing in the soil, the life cycle of trees spanning hundreds of years, and the animals and fungi lurking in the forest. In a theater deep within the forest, the trajectory and fragments of memories of the Mother Tree, which has watched over this forest, from its birth to its end, are depicted. The wind and mist that drift through the space stir the senses of visitors, and the climax is reached with a powerful performance in which layered images, music, and people merge. After the forest experience, visitors will explore the "Seeds of the Future" area, where over 700 cutting-edge technologies and initiatives from the Sumitomo Group are displays, leading to a platform utilizing generative AI where anyone can create and share ideas for the future. The Sumitomo Pavilion itself was constructed using approximately 1,000 cedar and cypress trees planted in 1970, the year of the Osaka World Expo. In addition to their experience at "UNKNOWN FOREST," visitors can participate in a "tree-planting experience" where they can touch seedlings and soil, and the newly grown seedlings will be returned to the original forest. This "story of life" will continue even after the Expo, and will be passed on to future generations.