Your city’s sister cities. How were they chosen?

My city (Kumamoto) has… San Antonio, USA, Rome, USA, Aix-en-Provence, France, Heidelberg, Germany, Guilin, China, Kaohsiung, Taiwan, and Fukui, Japan. San Antonio and Rome were chosen under the context of seeking closer U.S.-Japan relations post WW2, but were chosen because San Antonio and Kumamoto are cities nourished from spring water, and Rome and Kumamoto were both historical battle ground for their respective civil wars.

My city (Kumamoto) has… San Antonio, USA, Rome, USA, Aix-en-Provence, France, Heidelberg, Germany, Guilin, China, Kaohsiung, Taiwan, and Fukui, Japan. San Antonio and Rome were chosen under the context of seeking closer U.S.-Japan relations post WW2, but were chosen because San Antonio and Kumamoto are cities nourished from spring water, and Rome and Kumamoto were both historical battle ground for their respective civil wars.