Tall, bald, and muscular, Kukai is the largest and most powerful member of Team Kuu. However, in spite of his great size, his facial deatures are usually soft and relaxed, making him look similar to a monk. Kukai wears a standard, white martisl arts gi without sleeves, as well as a beaded necklace, which is actually his madogu.

Most of the time, Kukai has a relaxed, calm attitude, and rarely ever shows any signs of extreme emotion. He is also quite laid back, as seen when he'd rather relaxsitting in the grass rather than go to the tournament's opening ceremony. Kukai is also easy to befriend, as he quickly did so with Recca before their teams met in the ring, and stayed just as friendly with Team Hokage after the loss of Team Kuu.

In contrast, all these features vanish when his madogu has been activated. Kukai the Buddha. After his madogu has been activated, he turns into a demonic fighter who brutally attacks his enemies until they are defeated, as shown when he nearly beat Recca to death in their match. The real Kukai however is aware of his actions when in this state, and his intentions can still be pure.

(Source: Flame of Recca Wiki)