Gerda, the Ice Witch. While she is a genuinely friendly, amiable being, her intimidating exterior leads most visitors to her barrier to believe that she is dangerous. (This is not helped by their tendency to freeze almost instantly when she tries to approach them.) Resembling a large thistle made of ice, she inhabits a completely flat plain covered in snow, buffeted by howling arctic winds.
When the Witch doesn't try to approach visitors, they will find themselves greeted by her minions Edith and Roald. Edith is a beautiful, stately woman with salmon hair and green eyes, clad in a whitish-blue winter kimono. She arrives in a sled driven by Roald, her large, faithful sled dog. Edith will then start serving a delectable feast of steaming hot tea and bowls of Turkish delight on a small table stowed inside her sled's storage compartment, all while engaging her guest in pleasant talk. Those who find themselves approached by these two are advised to avoid the temptation and walk away as quickly as possible. Just a sip of her tea will be enough to induce hypothermic effects, and no one has been known to survive to the bottom of the bowl of Turkish delight.
This is Minami. Her Witch name comes from the female protagonist of Hans Christian Andersen's The Snow Queen, which is about the Devil turning himself into a mirror that only shows the bad in all beings and shuts out the good, thus making us look worse than we actually do.
Edith's name (guess who her image was based on) comes from Edith Ronne, the first woman to explore Antarctica. Roald's name is from Roald Amundsen, the first man to reach the South Pole.
The Turkish delight, of course, comes from the White Witch's temptation in The Lion, the Witch and the Wardrobe. Edith's actions were based on the Japanese legend of the Snow Woman (which was naturally alluded to and parodied in a lot of anime and manga).