On 27 February 2024, the biodiversity value of the Nagoya Higashiyama Forest was recognised and certified by the Ministry of the Environment as a ‘Natural Symbiosis Site’ (an area recognised by the national government as ‘an area where biodiversity is conserved through the efforts of private companies and others’).
Certified areas are registered in a global database of OECMs, except for areas overlapping with protected areas.

Nagoya City has set a target of certifying at least five Natural Symbiosis Site in the city area by 2030 in order to realise Nature Positive. To achieve this, Nagoya will apply for certification on municipal land and approach private land, as well as promoting Natural Symbiosis Site to the public.