I cant remember clearly but in this shoujo, a king (?) has to marry a princess, but when he goes to the princess's country, he just knows princess was a small kid (but he still falls in love with her, then force her to marry him)
http://www.mangago.zone/read-manga/koitomo_triangle/mf/c005/
Oops wrong place
Soredemo sekai wa utsukushi desu.
I cant remember clearly but in this shoujo, a king (?) has to marry a princess, but when he goes to the princess's country, he just knows princess was a small kid (but he still falls in love with her, then force her to marry him)