Where to sell concert ticket?

Hello,
I'm going to Tokyo end of April to visit a concert.
Due to circumstances I have ended up with 1 ticket too much.
Does anybody know where best to sell unwanted / not needed tickets (face value, of course)?
I know there's Yahoo auction, but this is somewhat complicated and longwinded from outside Japan.
Here in the UK you can just wave your ticket and ask if anybody's interested at the venue, on the day of the event, but I don't think that's too common in Japan, at least I never noticed anything like that.

Any advice would be much appreciated!
Thanks!

Here in Japan, it's common to wave your ticket and ask if anybody's interested at the venue, on the day of the event. But whether a buyer shows up or not is another story. A lot of people ask friends or fan sites in advance.

I heard it's not really legal to sell outside of venues, but I think the real case is that they don't want touts to sell so much over the regular price & make money out of it. So, if you see anyone with a sign looking for tickets, then sell it to them for the normal price, if you don't want to get in trouble. Whether someone will be looking, it depends on the act. I regularly go to YUI concerts & there is certainly no shortage of ppl holding signs for tickets! Another option to sell your ticket would be some of the concert ticket shops near to Shinjuku train station. You need to communicate in Japanese though.

Thanks for the advice!
Been to a few concerts in Tokyo, never noticed anybody offering tickets or wanted- signs , but I didn't really pay any attention as I had no need for them.
Maybe I try to look out this time.

Now, about the Shinjuku ticket shops, I arrive 4 days before the concert, would that leave enough time to sell it to them and get it sold on?
Also, where are the shops actually, never seen any, but also never loked for them.
Can anybody recommend any, addresses available or do they have websites?

Thanks!

just 4 days before the concert? hmm, not sure, depends on how popular the act is, i guess.
here's a map of shinjuku - http://www5d.biglobe.ne.jp/~LLLtrs/Links/maps/maps2/Shi...
If you find where Shinjuku Nishiguchi Station crosses Yasukuni Dori Avenue, that cross-junction is where a line of ticket shops is located. From JR Shinjuku, go out through the West Exit, go to street level, walk northwards along the main road, pass Sakuraya store on your right, a few ticket shops should be by a roofed pavement by that cross junction.

Hope this helps (^^)

Thanks justme, I think I know where that cross-junction is.

The event I'm going to is an open air festival in Hibiya Park with various bands / artists. Not current-chart success artists, but the top acts are well established bands with a strong fanbase.
I'm not sure it'll be a sell-out, at least not in advance.
There's still some regular tickets available.

Well, I'll seek out the shops on my first day there and see what can be done.