Does Japan have a LoL server?

I'm curious to know, does Japan have its own dedicated server for League of Legends, or do they have to connect to international servers for their gaming experience? It would be interesting to understand the gaming infrastructure in Japan and how it caters to the needs of its avid gamers. Is there a particular reason why Japan might or might not have a separate server for League of Legends? I'm eager to hear your thoughts on this topic.