Oukoku Monogatari  

Tales of the Kingdom, 王国物語

Story about two twins: one lives alone locked away in a tower and the other is a crown prince. What if they could trade places...?(Source: MU)

Originally published as a full-color one-shot Adolte to Adarte (アードルテとアーダルテ) in 2011 on pocopoco web magazine. Serialization of the series started in the May 2017 issue of the Ultra Jump magazine.