After being banned for more than 200 years, Catholic missionaries were allowed to return to modern Japanese society in the mid-19th Century. The Jesuits came back later than other religious groups, such as Paris Foreign Mission Society (MEP). However, after World War I, Spanish Jesuits began to live in Japan again, and they were sent to the Mariana, Caroline, and Marshall Islands ruled by Japan, at the request of the Vatican. At that time, these islands were under Japanese control, and Japan was promoting its colonial policies there. This study looks at the work of Spanish Jesuits in these islands. It focuses especially on several Spanish Jesuit priests and their interactions with non-Christian Japanese political leaders who governed the region, to defend the human rights of indigenous peoples. The goal of this research is to show the complex and transnational nature of the Spanish Jesuits' activities in wartime. In the presentation, I will consider their engagement with dynamics of in/equalities.