In English it's a philosophy. In Japanese it's the word 'improvement'.

What a Japanese person actually thinks
Corporate and mundane. This is a word from a meeting agenda or a suggestion box. Nobody in Japan hears it as a life philosophy.

Meaning

Literally: reform + good
Actually: Improvement. That's it. 業務改善 (workflow improvement), 改善案 (a proposed fix). The Toyota-production-system aura is entirely a Western export.

Scores

Naturalness●●●●●

Extremely common business vocabulary.

Coolness●●●●●

Two perfectly fine characters doing office work. The gap between its English mystique and its Japanese ordinariness is enormous.

Watch out

mediumTattooing 改善 is roughly equivalent to tattooing 'PROCESS IMPROVEMENT' in English.

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切磋琢磨 sessa takuma
polishing each other through effort and rivalry

A classical idiom about relentless mutual improvement. Everything kaizen means in English, with actual weight.
日進月歩 nisshin geppo
advancing by the day, progressing by the month

Continuous improvement as a four-character idiom rather than an office noun.

On skin

改善

Orientation: vertical

Mincho.