The famous ticket.co.jp?

ticket.co.jp is a resale site where you can get almost any ticket from Japan.
The catch? Prepare more money.
For ABC, try to avoid Yahoo Auction, BBS and mixi as possible. You can try on your on risk but be ready for in case your seats get blacklisted.

Morally speaking, ticket.co.jp is not a holy, pure, white site either (I was guilty for buying some ippan hatsubai tickets from there before as well), but it's the safest site in term of your money security as they implement some strict business rules at their website.

Just like the FC tickets, tickets from the lotteries and ippan hatsubai (general sales) tickets, if you have someone you know in Japan, you can ask them to buy the tickets for you from ticket.co.jp.

However, if you don't have anyone to help you, then you can use the deputy/shopping services as usual.

Below are some of the deputy/shopping services you can use:

FROM JAPAN
Kairai
i-TM4U
JE Goods (Don't worry, they also accept non-JE request!)
Treasure Japan
GOODY JAPAN
noppin (Please read their rules here.)

You can start surveying at ticket.co.jp after the general sales. Do not buy right away because the price will change from time to time. If there are a lot of tickets and people haven't started buying them yet, it's better to wait a bit longer, the price might drop later. Normally, if there are a lot of tickets, it's better to wait till as close as the performance date as possible. But if there are just few tickets and people already start buying them, it means the date is a hot date.

ABC page at ticket.co.jp can be found here.