Many of my male Korean friends now work in Seoul. I would have described their style as 'preppie' at university - a toned down version of today's Abercrombie & Fitch.
This translates well in the workforce to spread-collar blue or white shirts, fitted suits which give a hint of the shape beneath and beautiful silk ties.
Seoul is a demanding city with great extremes of temperature in winter and summer. Consequently, the favoured natural fibres include wool, cotton, linen, cashmere.
As they have become more senior, all my university friends have invested in a variety of suits with differing weights to deal with the extreme humidity of monsoon season, below-freezing temperatures for weeks at a time during the winter and constant travel around the region.