The right tail looks crooked, but otherwise the tails have a relatively strong structure.
Penducle is thick and strong. With a better tails, this can be a powerful fish.
Length of head a tad too long in proportion to the body, or read in another way, the body is too short for the head.
The left and right eyes' are not inline with the right eye too forward.
Looks like it is well kept, but I don't know how you could improve on the tails.

Cheers, and keep up the good work!
PS. Colour and patterns scores low in competition but they influence other aspect of judging. The single white cheek not only looks odd (but surely a nice conversation point) but the pattern is such it makes it looks bigger, and we know "balance" is very important for a ranchu.