Lake Suwa is a tectonic lake (13.3 km2) located on the central highland of the Japanese Archipelago at an altitude of about 760 m above sea level. This lake is world-famous for the long straight rows of ice ridges locally called OMIWATARI (Gods’ Crossing), that appear on the frozen lake surface in midwinter. The lake has been filled with sediments transported by rivers from its relatively wide drainage basin to become a typical eutrophic lake with an average depth of about 5 m. Nearly 80% of the drainage basin is covered by moor and forest vegetation, while the greater part of the human population is concentrated in a few cities near the lake shore. The higher industrial activity around the lake since the 1960s caused a rapid hypertrophication of the lake as indicated by heavy blooms of Microcystis spp. (blue-green algae) during summer. Accordingly, since the 1970s, measures such as construction of sewage systems and the removal of nutrient-rich sediments have been conducted, leading to observable improvements in water quality in recent years. At the same time, based on a master plan formulated by the Nagano Prefecture Government for lakeside development, efforts to restore ecosystems and promote tourism have been undertaken. Nonetheless, new challenges such as the proliferation of water chestnuts, the expansion of hypoxic water zones, and a decline in fish catches have emerged. Additionally, declining resident interest has become an issue, emphasizing the need to rebuild the relationship between local residents and the lake. Nagano Prefecture established the Lake Suwa Revitalization Vision (2038 Vision and Goals) in 2018, aiming for “a fascinating lake where humans and wildlife thrive together”. The second phase, Vision FY 2023– FY 2027, incorporates environmental research and educational initiatives at the Lake Suwa Environmental Research Center. By regularly reviewing this approach, it aims to address future challenges and drive continuous improvement.