The depression created between a woman's breasts via partial exposure of the chest. In anime, video games, and art, the cleavage is a popular method of adding some sexual appeal to the character. It should be noted that the cleavage is sometimes shown on characters as merely a curved line, while other times it has an extra, smaller line on the end, making the shape of a "Y" at the top of the depression.
If the charachter's breasts are not touching, use: breasts apart instead.
This tag is not to be used if the character's breasts are fully bared to the viewer, with no covering whatsoever.