These are Meoto Iwa 「夫婦岩」, sacred rocks representing the central deities in the Shinto creation myth, Izanagi and Izanami. The link between them symbolizes their union and that's why Meoto Iwa are also called the "wedded rocks" - it is a celebration of marriage - the larger rock is the husband and the smaller rock is the wife...
Travel tip: The beauty of the scenery is breathtaking, but be sure to visit Meoto Iwa during high-tide (you can use a tide predictor for the Toba, Mie area). At low-tide, the wedded rocks are no longer separated by water and some of the magic is lost...
EXIF info:
Nikon D90
Lens: 18-70mm F/3.5-4.5G
Focal Length: 35mm
Aperture: F/5.6
Shutter Speed: 1/800s
ISO Sensitivity: ISO 200