The style is an interesting combination of Western architecture with Japanese traditional elements: the lower part is similar to the walls of the Japanese castles (see, for example, the fan sloping wall from the Nagoya Castle), while the upper, octagonal-cylindrical part is typical for the Western lighthouses.
Called the Lighthouse of Kudan Hill (or Jotomyodai), the tower was built in 1871 and it is 12-meters-tall.
EXIF info:
Nikon D90
Lens: VR 18-55mm F/3.5-5.6G
Focal Length: 18mm
Aperture: F/7.1
Shutter Speed: 1/80s
ISO Sensitivity: ISO 400