Shōnen manga are stories written primarily with an audience of teen boys in mind. While shōnen manga series cover the full range of genres, including fantasy, romance, comedy, sci-fi, horror, and more, there are several stylistic features that characterise this category. There is often a focus on action and plot development, with plots often following the basic structure of the hero's journey. Rivalry and friendship are common themes encountered in this category, as well as the notion of the 'outsider' protagonist. Visually, shōnen manga often employs sharper edges and distinctive silhouettes for its characters.