●According to D.O, in one of their appearance in Sukira, age doesn't matter to him in dating even if the girl is as old as his mother. o_o
●D.O's ideal type of girl is someone who is beautiful when she smiles. He adds that it doesn't have to do with eye smile, just someone who radiates when smiling.
●D.O's eyesigh is not good. He has astigmatism. Thus, he wears content lenses. *this I'm not sure, it's tru or not.*
●D.O's favorite song of the XOXO Album is My Lady.
●D.O knows Jujitsu, a Judo move.
●D.O is close with Super Junior's Ryeowook.
●He featured in f(x)'s Goodbye Summer, a song part of f(x)'s Pink Tape Album which was composed by Amber and produced by Noise Bank, Henry's music team.
●D.O can imitate Xiumin's way of talking.
●It was revealed in a radio program that D.O walks around their dorm with his shirt on and his undergarment.
●D.O is close with BtoB's Hyungshik and Beast's Yoon Doojun.
●D.O's brother name is ,Do Seung Soo
●When asked about his little secret in a magazine interview, revealed he has a lot of moles on his body.
●During his 3rd year in high school, D.O admitted that he had a crush on his friend from another class.