During the interview, Junho said, "Even though Lee Yu Bi and I are both born in the year 1990, I told her to call me 'oppa'. It's because I have an early birthday so I get sensitive about these things." 

Junho's birthday is on January 25th while Lee Yu Bi was born on November 22nd, making her almost ten months younger than the idol star. This also means that Junho would probably have gone to school with mostly 1989-ers due to his early birthday and consider them his same-age friends.

SEE ALSO: Krystal's past letter to late f(x) member Sulli goes viral

Junho explained the reason why he wanted Lee Yu Bi to call him oppa and rather than considering him a same-age friend, saying, "I can't really be 'friends' with people who were born in 1990, my friends are all born in 1989 so I can't have that get mixed up. Kim Woo Bin was born in 1989 and Kang Ha Neul has an early birthday in 1990, so I was able to be friends with him. I know it seems childish, but because I have friends [who are older], I have to keep it [that way]." 

The idol-turned-actor also complimented Lee Yu Bi on her charming bubbly, energetic personality and said that she is easy to get along with.

Meanwhile, Junho will appear in the upcoming movie, 'Twenty,' taking on the role of Dongwoo who dreams of becoming a comic writer. 'Twenty' will premiere in theaters on March 25th!