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Dan's father (Japanese: ダンの父 Dan's father) is a minor character of the day in A Sandile Gusher of Change!.
Dan's father owns a Spa Resort on Route 1, a resort famous for its sand baths. He works there with his son, Dan. He first appears in a flashback where Dan tells Ash and Iris about the Sandile incident that has been occurring quite often for a few days where they are scaring customers away.
Later Ash, Iris and Dan tags find out that the reason the Sandile are scaring the people away is that the geysers are erupting. Later it is seen that the geysers have done more good than harm and have put Dan and his father back in business with a brand new hot spring, which he treats Ash and Iris to.