I confirmed in Takao Gothic (ttf-takao-gothic) and VL Gothic (ttf-vlgothic)
I copied this text to gedit and checked following things.
In unicode,
"ループバック" is "\u30eb\u30fc\u30d7\u30d0\u30c3\u30af"
garbled text is "\u30eb\u30fc\Uffffffffg \u30c3\u30af"
I confirmed in Takao Gothic (ttf-takao-gothic) and VL Gothic (ttf-vlgothic)
I copied this text to gedit and checked following things. u30fc\u30d7\ u30d0\u30c3\ u30af" u30fc\Uffffffff g \u30c3\u30af"
In unicode,
"ループバック" is "\u30eb\
garbled text is "\u30eb\