For those of us who wonder why Yoochun shuns socks and full length pants, a Bigeast fan actually asked this question. And we have an answer. (btw, this is from a Bigeast in January, but Yoochun's socklessness ever goes old.)
CM :‘Hello THSK. You always travel back and forth between Japan and Korea, are you still doing well. I am really worried, especially about Yoochun’s legs. It’s winter, but his pants are short or three quarters long. And also, seeing his shoes, I want to ask him. Does he not like wearing socks ? Or doesn't he have any ? (XDDDDD)
YC : Ya, I do have socks. (YC is super amused here)
CM : I am really not careful today (regarding his choice of letter to read.)
YC : I do have them. But I like the feeling of being cold.
CM : How strange.
YC : I really like that cool feeling on my body.
CM : I understand this, but to open the biggest window in the room …
YC : I don’t do that anymore … really.