Persistence is the best counter to Kyoko. Since Kyoko can only survive 4 attacks at maximum without healing cards and possess no ability to evade, the player should attack Kyoko often to deplete her health quickly. By doing this the opponent will either be KO'd or be forced to spend 20 stars and use Crystal Barrier. Either outcome will cause star loss for the opponent.
Card control such as Gift Exchange and Flamethrower have the potential to be devastating to Kyoko the inability to evade will often mean Kyoko needs healing cards to keep her HP up.
Reverse Attribute Field is deadly against Kyoko as it will turn her DEF stat to -3 and give her a powerful evade stat she can't use. As a result, the opponent will only be able to roll 3 or lower for defense without assistance, likely resulting in a KO.
Sink or Swim can be used when Kyoko is at 1HP to steal 75% of her stars