Kai Mayonaka has twelve siblings and a mom and dad, the eldest brother/sibling Kenji, Jen eldest sister, Daichi 2nd eldest, Kikai and Kenzo twins 3rd eldest (girl and boy), Kai himself 4th eldest, Mika 5th, Mia 6th, Kuro 7th, Kira 8th, Naoko 9th, and Ako last. Two parents are Sho and Yori. They all are ninjas, some training and some fully trained. His favorite place is the ancient scroll site.