The Gapsin Coup broke out in December 1884, which is considered as a trigger for the annexation of Korea, and it is said that Inoue who was deeply involved in the coup, fled to Japan together with Ok-gyun KIM and Yonghyo PAK.
1884年12月に朝鮮で起こった甲申政変は、韓国併合の契機となったといわれるが、この事件に井上は深く関与し金玉均・朴泳孝らと共に日本に逃れたとされる。