Futari no Himitsu

The protagonist, Saijo Hime, is a popular idol and model, but she's actually very easily embarrassed and shy despite her profession. At school, she is troubled by the hoard of fellow classmates asking her for autographs and photos. Her longtime crush Takumi-kun comes to her rescue.

However, her first kiss goes to a boy named Igarashi Teppei by complete accident! ...Wait a minute, something's not right here. They've switched bodies!?

(Source: Wild*Hope)