Sorinbaru Memorial Tower is a historic memorial monument located in Kawaminami Town, Koyu District, Miyazaki Prefecture. Designated a National Historic Site in 1933, it is an important place associated with the history of Kyushu. The tower was built to commemorate those who lost their lives in the Battle of Taka Castle, also known as the Battle of Mimikawa, during the Sengoku period (Warring States period) of Japan.
Sorinbaru Memorial Tower was erected to honor those who died in the Battle of Taka Castle, also known as the Battle of Mimikawa. This major conflict in the struggle for control of Kyushu took place on November 12, 1578.
The Shimazu and Otomo clans fought fiercely in this battle, which resulted in many casualties. The memorial was built as a six-Jizo tower to pray for all those who had died, regardless of which side they had fought for. Its construction is believed to have taken place during the spring equinox period in February 1585. Yamada Arinobu is said to have paid the entire cost of its construction.
The tower was made from hard tuff quarried in the Kiyotake area of Miyazaki Prefecture. This durable volcanic rock is highly resistant to weathering and was chosen for its ability to withstand the passage of time.
However, the monument was damaged during the anti-Buddhist movement known as haibutsu kishaku, which took place in the Meiji period (1868–1912). It was destroyed and discarded at the bottom of a local valley called Jizodani, or Jizo Valley.
According to local tradition, residents returned the remains of the tower to its present location during the Taisho period (1912–1926). However, no detailed records of this restoration have survived.
All six Jizo figures on the memorial were damaged with tools during the anti-Buddhist movement. Even relatively minor damage includes the removal of the figures’ noses, while other parts have suffered substantial losses.
The tower no longer has its original base, and large areas of damage remain on the lotus-petal sections. The balustrade that once stood beneath the six Jizo figures is also missing. In addition, the uppermost finial and umbrella-shaped roof are not the original components; they were placed on the monument as temporary replacements when it was restored.
Restoration work was carried out during the Taisho period. By the time the site was designated a National Historic Site in 1933, the monument had already been preserved in much the same condition as it appears today.
Later, during agricultural land improvement work in Jizodani, a component believed to be the original umbrella-shaped roof was discovered. However, it was reportedly discarded without being formally reported, and it has not been preserved.
A memorial mound stands behind Sorinbaru Memorial Tower. It measures 80 shaku on each side (approximately 24 meters) and was once enclosed by a wooden plank fence.
To the south of the mound was a ceremonial area measuring 40 shaku on each side (approximately 12 meters), surrounded by a ditch. The remains indicate that rituals and ceremonies for the deceased were conducted here.
Evidence found beneath the surface soil, including volcanic glass, has revealed that the surface of both the memorial mound and the ceremonial area was covered with Akahoya, a layer of volcanic ash.
Sorinbaru Memorial Tower is a valuable historic monument built to mourn the victims of the Battle of Taka Castle, one of the major conflicts in Kyushu’s history. Its background, together with the destruction caused by the anti-Buddhist movement and the subsequent restoration, reflects the changes that Japanese history and religious culture have undergone over the centuries.
Although the tower has suffered considerable damage and no longer retains all of its original components, it remains protected as a National Historic Site. It continues to convey the history and cultural heritage of the region, offering visitors an opportunity to reflect on the people who lost their lives in the battle and the later generations who sought to preserve their memory.