Because he was a child with a running nose depending too much on his mother until the age of 17, he was nicknamed "big fool" by being compared with his elder brother Yukitaka (he served Emperor Komei, Takamori SAIGO praised him by saying the Restoration would not have been accomplished without Yukitaka).
17歳まで洟（はな）を垂れて母親に甘えていたので、兄の敬孝（孝明天皇に仕え、西郷隆盛に、敬孝がいなければ維新は成らなかったと言わしめた）と比較されて「あやバカ」とあだ名された。