inscrutable/measured

Koreans are hot, aggressive, energetic, emotional and upfront; while Japanese are cool, polite, measured, calm and inscrutable.

inscrutable   /ɪn'skruːtəbl/   adj)人の表情などが不可解な

★ (especially of a person's expression) impossible to understand or interpret

・He was wearing that inscrutable look again.

・Her face had become inscrutable.

・inscrutable to somebody   Unfortunately, this language is largely inscrutable to non-specialists.

measured   /'meʒərd/　adj)慎重な・控えめな

★ slow and careful; showing control

・She replied in a measured tone to his threat.

・He walked down the corridor with measured steps.

upfront   /,ʌp'frʌnt/　adj)率直な･ざっくばらんな

★ upfront (about something)   not trying to hide what you think or do

・He's been upfront about his intentions since the beginning.

threat   /θret/   n)脅迫

intention   /ɪn'tenʃn/　n)意図･意向･目的