Kairi is a Premium Box Tsum. She is a limited event Tsum and is not available from purchasing Premium Boxes outside of the event. She was introduced during the Japan Event Stitch's Cousin Search (September 2018) and the International Event Stitch's Cousin Frenzy! (January 2019). On the Japanese version only, she is also a voice Tsum.
Kairi will summon Sora and they can be connected together for large scores. Her base number required is 22 and her base number transformed is 4. Higher skill levels reduce the number required.
Sora and Kairi can be connected together regardless of the distance. The Soras also clear surrounding Tsum Tsum.