
Sakura is a legit surname too, IMO. I'm not sure how "modern" it is, but it is not an uncommon surname. You can definitely use it if you like it, just not the sakura tree version 
Heck, the surname I'm using was completely made up and I've never seen the name used in real-life Japan. Ever. But I believe it fits the Raen lore nonetheless. You need to keep in mind that Othard is not Japan. They only borrowed ye olde Japan's naming convention =]
Edit: Grammar.

Heck, the surname I'm using was completely made up and I've never seen the name used in real-life Japan. Ever. But I believe it fits the Raen lore nonetheless. You need to keep in mind that Othard is not Japan. They only borrowed ye olde Japan's naming convention =]
Edit: Grammar.