According to Research Director Sota Kato, Japan's impasse in trade negotiations with the US is attributed to an impractical, principle-based approach and a lack of decisive political leadership needed to make difficult concessions.

"‘We will not be taken for fools’: Under election pressure, Japan PM stands firm on trade with US," The Straits Times
https://www.straitstimes.com/asia/east-asia/we-will-not-be-taken-for-fools-under-election-pressure-japan-pm-stands-firm-on-trade-with-us

Profile of Research Director Sota Kato
https://www.tkfd.or.jp/en/experts/detail.php?id=29