Hiiro no Shiro
Synopsis
Edward is suddenly taken under the wing of Sir Burton, a man who lives in a great red mansion. Although he doesn't know why he was invited or who that beautiful lady he spotted is, he's about to find out the mysteries of the scarlet castle... (Source: Irodori Comics)
Background
Hiiro no Shiro was published digitally in English as The Scarlet Castle by Irodori Comics.