This memorial commemorates the arrival of Portuguese ships. Kuchinotsu was already a flourishing trading port by the sixteenth century; the area known as the tojin-machi (“Chinese quarter”), for example, points to the presence of visitors from the Asian mainland. Portuguese merchant vessels, however, first came to Kuchinotsu in 1562, when Arima Yoshisada (1521–1577), father of the Christian daimyo Arima Harunobu (1567–1612), granted them permission to trade there. Portuguese ships dropped anchor here a further five times between 1567 and 1582, building up a relationship with the Arima domain not only through trade, but also by lending money and supplying weapons. In 1563, merchant-turned-Jesuit-missionary Luis de Almeida built a church here. In 1564, Cosme de Torres, the Japanese mission superior who had first come to Japan in 1549 with Francis Xavier, elected to make Kuchinotsu his base. It became such an important port that Father Alessandro Valignano, the Jesuit Visitor who oversaw the order’s activities in Asia, selected Kuchinotsu as the venue for a 1579 meeting of foreign missionaries from throughout Japan.

The memorial’s inland location is the result of land reclamation over the years. The area around the memorial, which is now a park, was originally reclaimed for rice cultivation.