1. Faculty of Environment and Information Studies, Keio University, Fujisawa, Kanagawa, Japan
2. Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata, Japan
3. Graduate School of Media and Governance, Keio University, Fujisawa, Kanagawa, Japan
4. Spiber Inc., Tsuruoka, Yamagata, Japan
5. Laboratory of Biodiversity Science, School of Agriculture and Life Sciences, The University of Tokyo, Tokyo, Japan