Butterfly Kyodai follows most of the standard mahjong rules. You must match pairs only around the outside of the board. Butterflies that are blocked by other pieces won't count unless they are directly beside each other.
Place the butterfly in a jar with a wet paper towel for 2-7 days. When butterflies die, their bodies become very brittle and will break apart easily unless they're relaxed. Wet a paper towel with warm water and set it on the bottom of a glass jar with a lid.