Sanae's bubble is colored blue instead of the usual green.
Because she's cold.
Hoeh…This is a man-made cave for excavating the "Ooya stone"It's a bit cold isn't itApparently the temperature is always regulatedI wonder if we can hold a convention hereHow about something like Gurren Lagann?I wonder if it's an occupational diseaseIf you're gonna, then it should be for something like Subterranean Animism.