was a Japanese legal expert during the Meiji period. In addition to law, he also studied sociology at Tokyo Imperial University. During the Sino-Japanese war, he advised Field-Marshall à Âyama Iwao on issues of international law. In 1913 he accepted the invitation by Yuan Shikai, to prepare a draft constitution for the new Chinese republic, together with . Ariga doubted that China was ready to implement a liberal democracy and recommended a balance between monarchy and republic.
Ariga also worked as a translator.