This isn't miscellaneous characters added for visual effect, it's the title of the work written in two languages. (The katakana isn't stylistic, by the way - it's standard Japanese, apart from how it's positioned.)
Of course I realize that it is the title of the work and I also know that it is standard Japanese (I've lived in Japan for 9 years and currently live there). What I mean by stylistic is that the katakana title only serves as visual flourish and not that the katakana writing itself is written in a particularly stylistic way. This isn't a bilingual site or article, everything else on the site is written in English.