- Erume City is a fictional city in the Hatoful Boyfriend video game series. It is located in a post-apocalyptic world where birds have taken over as the dominant species. The city is known for its various landmarks and locations, including St. PigeoNation's Institute, a prestigious high school for birds. The cityscape is a mix of urban areas and natural environments, with buildings and trees intertwined in a unique and artistic way. Despite the avian apocalypse, Erume City remains a vibrant and bustling city, with many birds and humans coexisting and going about their daily lives.