Kyoumen no Silhouette

Kyoumen no Silhouette summary:

Eruna was entrusted with ruling a country at a very young age when her father, the king of a small kingdom, fell very ill. With such a heavy burden placed upon a mere teenager, the king gave Eruna an important piece of advice about how he made his time of rule a success: find your shadow. By finding her double, she will find the will to live and be brave even in the most dire situations. Eruna does find a person who looks identical to her but it turns out fate loves to play games. Teshio used to be a simple rancher who had a problem of always being mistaken for a girl but he is about to go from rags to riches because he becomes the new shadow for princess Eruna.