주환 (Joo-hwan) is a fairly common Korean male name; the hanja
宙 'cosmos/space' +
焕 'bright/radiant' literally read as 'shining cosmos' - typical of the auspicious meanings parents pick when assigning hanja. You'll see
宙焕 in Chinese subtitles for K-dramas; the hanja
焕 itself is favored in Korean men's names (also
焕基 Hwan-gi,
在焕 Jae-hwan).
