Fabric: linen (or linen mix) — Linen is highly breathable, moisture-wicking, strong and durable. 
LGlinen
📌 My suggestion for you (given you’re in Chennai)

• Go for 100% linen if possible, especially for comfort in warm climate.
• Choose something with short sleeves or lightweight long sleeves depending on how formal you need it.
• Pick light or muted colours (cream, light grey, pastel, soft green) because they’ll reflect heat better and fit the Korean aesthetic.
• If you’ll wear it often and want easier maintenance, consider a linen-blend or cotton/linen blend so it wrinkles less and is a bit more forgiving.
• Pay attention to size/fit — Korean style often runs a bit more relaxed/oversized, so if you prefer fitted look adjust accordingly.