Wonder Boy (ワンダーボーイ Wandā Bōi) and the later Monster World (モンスターワールド Monsutā Wārudo) make up a series of video games published by Sega and developed by Westone Bit Entertainment (formerly Escape). The series itself consists of the main Wonder Boy series, and the Monster World sub-series. Games may be part of one, the other, or both. This has resulted in a sometimes confusing naming structure resulting in titles like "Wonder Boy V: Monster World III". North America and Europe received every game that was under the Wonder Boy brand, but Japan received one exclusive title that is exclusively part of Monster World.