Some researchers have recently coined the notion of ‘Nature’s contribution to People’ along with the notion of ‘relational values’ to broaden the existing notion of Ecosystem Services (ES). These researchers argue that the current frameworks for assessing ES, such as Millennium Ecosystem Services Assessment (MA), are heavily dependent on the contribution from the ecologist and economists and they are ignoring the contribution from other social sciences, such as sociology, anthropology and ethnography.
 Despite the fact that these newly created notions are fiercely debated in international forum like The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), these notions are still at their nascent stage. Further development of these notions is yet to be desired, especially by establishing concrete case-studies. This research aims to conduct three case studies, both in Japan and US, to reveal the ‘relational values’ and to develop the methodology for assessing these values. It especially focuses on the relational values that are developed through the maintenance of livelihoods. Further, this research aims to introduce these case-studies and the methodology to international platforms like IPBES. By doing so, this research critically assesses the current existing environment policy which seeks economic efficiency and opens a path for new environmental policy which incorporate the voices of the local population.