aSchool of Economics & Management, Kochi University of Technology, Kochi

bGraduate School of Integrated Arts and Sciences, Hiroshima University

cGraduate School of Humanities and Social Sciences, Hiroshima University, Higashi-Hiroshima, Japan

Received 16 May 2023 Accepted 3 June 2023.

Correspondence to Keiko Ogawa, PhD, Graduate School of Humanities and Social Sciences, Hiroshima University, 1-7-1, Higashi-Hiroshima, Hiroshima 739-8521, Japan, Tel: +81 82 424 6580; e-mail: [email protected]