Buying japanese concert tickets?

[Alixx!]

I was wondering if any body could give me some advice on how to book tickets to a concert because me and my best friend are dyingg to go to koda kumi's new tour but I don't have a clue how i would get the ticketss!
Is there any english websites/ places I can buy themm?
I have a rough knowledge of kanji/hiragana soo it would take me forever to translate a website page haahaa any help would be very mcuh apreciated
Thankyouu xxx