Those who are possessed are born two months premature and transform into their Tailed Beast States if they are hugged by a person of the opposite sex, or if they are under a great deal of stress (such as exhaustion, sickness or lack of breath). Like the Sohma Clan's Curse and Uchiha's Curse, They do not transform into animals if they are hugged by another member of Gekko Clan or a member of the Sohma Clan.
The Cursed OnesEdit
Yamata no Orochi: Paul GekkoEdit
Paul Gekko was possesed by the Great Serpent with Eight Heads but only because with the loss of the Older Brother it is shown that Kaede Gekko used to be with Kyoji and Mira Gekko before Paul was born. Thetis and the Other members of the Gekko inherited that curse for many years.