Here is the male version of handsome male actors in natty school uniforms before and after debut--enjoy! 

SEE ALSO: Then and Now: Actresses in school uniforms before and after debut

Jang Geun Suk

Kim Soo Hyun

Kim Woo Bin

Lee Jong Suk

Lee Min Ho

Park Hae Jin

Park Seo Joon

Song Joong Ki

Seo Kang Jun

Yoo Ah In

Kim Bum

Park Bo Gum

Ryu Joon Yeol

Song Jae Rim

Bonus: 

Yeo Jin Goo

Yoo Seung Ho