HERO'S new weightclass is 63kg? or 65kg?

MMA k-1

K-1's making new weightclass is clear,but this limit is unclear,
This new class maincast is YAMAMOTO"kid"Norifumi,he is maineventer of HERO'S,absolute big star,
his best weight is 63kg.
i think if This catagory is established,YAMAMOTO is perfect king in it too.
But many other Good talents are 65kg,TAKAYA hiroyuki ,TOKORO Hideo, and A,F.Noguiera.......
HERO'S choice in important for USA lightweight fighter too.