The four boys who went to Europe returned to Japan with a printing press, which was intended to help spread the Christian Gospel far and wide. Catechetical works such as Dochirina Kirishitan and Santosunogosagyo were printed in Kazusa in Minami-Shimabara, and were used in Christian missionary work.

Such things as art and music were also made use of. The missionaries knew that by appealing to peoples senses they could effectively preach the Gospel to people of all ages in a way that was easy to understand. In this area, the oldest copperplate engraving in Japan (Our Lady of Seville) remains. Its delicate line engravings were done by a Japanese person using the kind of skilled artistic techniques that were nurtured within “seminario” and other such establishments (“seminario” were Christian institutions which provided primary education). In Arima, not only copperplate prints but also such things as oil paintings and watercolour paintings were made. These showed such a high level of skill that they could easily have been mistaken for having been made in Rome, and they were praised by the missionary Frois.

Even after Christianity had been officially banned in Japan, the four ambassadors who had returned from Rome were granted an audience with Toyotomi Hideyoshi (as an embassy from the viceroy of India), where they delighted him by playing western musical instruments.