The jrpg label came about recently with the emergence of western rpgs on consoles (Morrowind, KOTOR, Fable) to differentiate the freedom-oriented style commonly found in Bethesda/Black Isle Studios/Bioware/ games (the major western producers of rpgs) from the scripted linear story-telling style found in most Japanese RPGs (Final Fantasy et al).
Bethesda, Black Isle and Bioware were inspired by the freedom and role-playing aspects found in Dungeons & Dragons and other pen n paper rpgs. The vast majority of Japanese rpgs weren't (though I suspect Shin Megami Tensei was). They have been mostly influenced by Wizardy (a dungeon crawling computer rpg with not much in the way of freedom or roleplaying) and later on by Japanese anime and Japanese culture and pop culture. Basically Wizardry bred with Japan and that's pretty much it.
As for Valkyria Chronicles, you have to look back to Fire Emblem. Fire Emblem is a combination of the rpg mechanics brought over from Wizardry and war games (apparently war games were an influence on Fire Emblem). It's also worth noting that the staple SRPG battle system that Fire Emblem pioneered looks awfully a lot like Ultima III's battle system. Maybe Ultima III was an influence?
Honestly I'd say Fire Emblem, Shining Force and Valkyria Chronicles belong to a genre of their own. They may be Japanese and have RPG elements but I see no point in lumping them in with Dragon Quest, Final Fantasy and what not. If you called Diablo a wrpg just because it's a western developed game with rpg elements, you'd probably piss off a lot of Bethesda/Bioware/Black Isle fanboys. I consider Diablo a dungeon crawler or Action RPG. Just like I consider Fire Emblem, Shining Force and Valkyria Chronicles to be strategy RPGs (I'd call them turn-based strategy games but I suppose I might offend Civilization gamers if I did. lol)
Actually you know what there is so much diversity within the RPG spectrum (even within the japanese and western ones) that I really don't feel like coming up with labels. There is a lot of diversity. You have turn-based rpgs. Real-time rpgs. And then you have adventure orientation, dungeon crawling orientation, scripted storyline orientation, hack n slash orientation, role-playing orientation (I'd argue this would be SMT), strategic orientation, etc. And often times you get mixing. Genre labels don't do things justice. You need to explain what a game is like in at least one sentence. Sometimes you need more than one sentence.
