Kanten comes in many types, from powder, to threads, to dried blocks. The trick is to get the ratio right. We used a powder that I was not familiar with and the sweets turned out to be so hard they were like hockey pucks and had to be discarded.
Molding the koi for the most popular sweet was like sculpting with play-doh. The fish are made with white an and then orange and yellow bits are added randomly for color.
And for the inspiration of koi in the pond: