APFELLAND MONOGATARI

Apfelland is a small but beautiful country surrounded by Russia, Austria, and Germany. Vel is a boy who lives in the capital, Charlottenburg. He happens to help a girl named Frid. She was kidnapped because a radium mine was found in her grandfather's abandoned mine. Various people gather there, such as a money-hungry American, a revolutionary Polish woman disguised as a man, and the ministry of Apfelland that plots to affiliate with Germany. Vel and Frida are involved in their stories, as they know the secret of the mine. (From AnimeNfo) — Description from AniList community (anilist.co).