noun
A person who insists on flawlessness and sets extremely high standards.
彼は完全主義者だから、小さなミスも許せない。
He's a perfectionist, so he can't tolerate even small mistakes.
Often used interchangeably with 完全主義者, but 完璧主義者 emphasizes a pursuit of absolute perfection, while 完全主義者 focuses on completeness and flawlessness.
Compound of 完全 (perfection, completeness) + 主義 (principle, doctrine) + 者 (person).