Having grown tired of Marisa constantly bringing home big hauls of books from the Voile Library, Patchouli Knowledge attempts to stop the incessant theft by stashing her books in her newly-created castle and hires several other characters to protect her palace. But Marisa, aided by Alice, sets out to defeat her friends before making a climactic raid on Patchouli's trap-laden castle to bring home another big haul of books.
This game is considered "one of the hardest games ever", since it is a clone of the Mega Man games with the Danmaku shooting tradition of the Touhou series.
