The Rain (雨) is a mischievous entity that is able to control rain and create suprising downpours on anybody to prank them. Rain is The Cloud's twin, and in the anime its water gives the Wood enough power to cause chaos in Sakura's house (Episode 4). Sakura sealed Rain with help from the Watery, which was also able to feed off Rain's power to increase its own. Rain, as a free spirit, is very chaotic and tried to drown Sakura with a waterfall-like attack to play with Sakura, like Cerberus said. It is under Watery.