Depends on the game and how well it is at sucking me into the story but id say an 25 to 30 hour jrpg usually takes me about 2 or 3 weeks to finish depending on real life events.

Ill use Final Fantasy VI Advance as an example since its the current JRPG im playing. I started it 4 days ago and i am currently 16 hours in which i would consider faster then my average but its FFVI and i havnt completed it in almost 2 years! The woes of an JRPG player is you always have a big backlog :(

It makes me sad when I look at my backlog and all I see are RPG, RPG, RPG.

lol >_<

Kingdom Hearts is a series that always take me forever to beat.

I play Pokemon games usually within about a month (I like to replay one of these these and/or play the new ones usually every year) I can usually finish a Final Fantasy Tactics replay within a few days if I'm trying but the typical playthrough when I'm just having fun is a week or two. Another old JRPG I replay sometimes is DBZ: The Legend of the Super Saiyan and the last time I played that (a week ago) it took me three days (with work) which was quite fast for me.

Took me about 3 weeks to play Fire Emblem: Sacred Stones back in January, and then maybe 2 weeks to play through Fire Emblem: Awakening (although I still pick this up to play new DLC/Paralogues, etc. but that's a different story).

I suspect it takes me longer to play through most games than the average gamer though as I have a full time job and additional responsibilities beyond that that give me very little free time.

125? Try 200+. :) Don't know if you meant beat the main story or 100 percented the game like I did.

OT: It takes me FOREVER to finish them, because I like to do every possible thing there is to do in the game. I actually use to be even more OCD than I am now: I would restart from save points from an hour ago or replay tough battles just to hear every possible dialogue tree... Oh my gosh, I had issues! Thank God I discovered script FAQs online.

It took me a month to beat Chrono Trigger back in November last year, and that's probably the shortest RPG I've ever played. Xenoblade took a good 6-7 months (though I stopped playing every day after the 150 hour mark), and that's probably the longest. I'm probably the slowest gamer you'll ever meet in your lfe, which is why I'll never own more than one current gen console at a time.

In terms of real time I really don't know because I always have stuff to do and can't game all the time. If I'm on vacation I can maybe finish a normal JRPG in about a week or so, but if I'm busy it may take me 1 or 2 months.

It took me a month and a half to finish SMT IV, but the in-game time was 56 hours I believe. 

40-50 hours on the story, about another 50 mucking around questing and what not.

Depends on the game. I have 198 hours in New Vegas but that wasn't just one play through.

It depends on how good or bad the game is. It can take me anywhere from a week to a month, to a few years or never finish the game at all.

If it's boring I might put the game down frequently. If it's enjoyable I might forego sleep to keep playing.

it depends of the game... xenoblade about a month, P3P about 2 weeks... SMTIV I already have a couple of weeks and it looks like I still have a lot to do...