Training as a spiritual practice — not going to the gym.

What a Japanese person actually thinks
Respected and slightly severe. It implies a long apprenticeship under someone harder than you. People will assume you mean it.

Meaning

Literally: cultivate + go/conduct
Actually: Ascetic or devotional training. What a monk does in the mountains, and what a craftsman does for a decade before being allowed to work alone.

Scores

Naturalness●●●●●

Common word, used both religiously and about any serious craft apprenticeship.

Coolness●●●●●

Two solid characters, and a meaning that says something specific about how you approach things.

Watch out

lowIt implies submitting to a discipline under a teacher. If your idea was self-directed hustle, 鍛錬 (tanren, forging oneself) fits better.

On skin

修行

Orientation: vertical

Mincho.