Gender: Masculine
Origin: Japanese 雷神
Meaning: “thunder god; thunder spirit”
Japanese (RYE-DEN); Eng (RAY-den)
The name is composed of the Japanese elements, 雷 (rai) meaning, “thunder” and 神 (shin), meaning, “god; spirit.”
In Japanese mythology and in Shinto religion it is borne by a fierce god of rainstorms and everything associated with rainstorms.
Currently, Raiden is the 639th most popular male name in the United States, (2010). Its recent rise in popularity is most likely due to Japanese-American parents looking for a name that honours their heritage yet is easy to say and spell in an English-speaking country.
Another transliteration is Raijin.
Source
Oh my god, I haven’t checked in a few weeks and totally missed that you’re posting again! Welcome back. 🙂
As for Raiden, I think its popularity might be more due to the overall trend of “-aiden” names in the US right now. I’d be surpirsed if most of the people with a little Raiden even knew it’s Japanese.