Sea

Sea is the core of the ocean, and the only one of the four main cast with less than half a body. Other than his head, shoulders and arms, Sea is a column of running water that flows out of his head and chest, then back up under his surface. The constant rushing water in such a short distance (his height) makes it impossible for fish to inhabit him, and this make him incredibly sad. Despite this, he is normally cheerful and hyperactive, often dragging Sun and Cloud together with him on his land adventures and even out into the water. 

fun fax:

--Cloud and Sun are the only two of his three friends who could kill him with little effort (electrocution from Cloud and boiling/evaporating from Sun). Despite this, he cares deeply for the both of them
--even though he holds massive amounts of affection for Sun, his heart is still inclined to Crescent and his phases
--he cannot get lost in himself if he steps into the ocean as his core. even though his core is also made of water, if Sea attempts to interact with himself, his core body will remain separated from the rest of his real body.