 King Sebastian feared that it was having a negative effect on Catholic proselytization since the slave trade in Japanese was growing to massive proportions, so he commanded that it be banned in 1571.Records of three Japanese slaves dating from the 16th century, named Gaspar Fernandes, Miguel and Ventura who ended up in Mexico showed that they were purchased by Portuguese slave traders in Japan, brought to Manila from where they were shipped to Mexico by their owner Perez.Japanese slave women were even sold as concubines to black African crew members, along with their European counterparts serving on Portuguese ships trading in Japan, mentioned by Luis Cerqueira, a Portuguese Jesuit, in a 1598 document.