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Article History

Received: 4 May 2025

Accepted: 7 May 2026

First Online: 19 May 2026

Competing interests

: The authors declare no competing interests.

: Ethical approval for this study was obtained from the University of Tokyo Graduate School of Engineering Ethics Committee (Approval Number: KE22-30). The study was approved on December 19, 2022. All research procedures involving human participants were conducted in accordance with the ethical standards of the institutional research committee and with the Declaration of Helsinki and its later amendments or comparable ethical standards.

: Informed consent was obtained orally from all participants prior to their inclusion in the study. This approach was adopted due to COVID-19 restrictions and organisational logistics, which made written consent impractical. Consent was obtained directly by the principal researcher on the day of each interview (see Table 2 for specific dates), and the process was conducted using a standardised oral script. Participants provided oral consent after being fully informed about the study’s purpose, procedures, and their rights. The consent covered the following aspects: the aim of the project; the method of data collection (interviews); assurance of data confidentiality and anonymity; secure data storage and retention; the voluntary nature of participation and the right to withdraw at any time; the intended use of data for academic publication; details of ethics review and approval; and the data protection measures in place. Participants also consented to being audio-recorded (or alternatively, having notes taken), being re-contacted for clarification, and using anonymized direct quotations in research outputs.