"Milka appears in episode six under the care of Seiren. She is a girl with a cruel past who is trapped in her five-year-old body. Milka lives on an island, and has no one to befriend but Seiren and her white tiger, Rascaless. Her initial caretaker was an older woman who used to whip the child as a punishment for such trivial offences as talking back to her. Eventually, the old woman is killed by Rascaless when Milka isn't watching. Initially afraid of Hazuki and Lilith, she warms up to them and has Seiren take them to the villa at the center of the island.

Milka's world is subject to periodic reality shifts she calls "rip-rip", during which the sky and the ground rip open as if in an earthquake, only to close without a trace. These drive Milka wild with pain, and she collapses at times. At one point, a "rip-rip" splits the sea, and Milka wanders into the gap, mumbling about crossing the ocean. The rip closes and she is nearly drowned. Hazuki attempts a rescue, but it is Rascaless who saves Milka. Afterwards, Milka realizes Rascaless killed the old woman for her; she thanks him, but asks him never to do such a thing again. Back at the villa, it is revealed that Seiren was grooming Milka to use her magic against Lilith, as revenge for abandoning her. However, Milka apparently has no magical powers even though she does not age. Lilith shrugs it off and tries to reconcile with Seiren, and then sends Milka across the ocean on a ship, at her right age.

In the game, Milka is sent to live on the island by her older brother, for whom she has romantic feelings, because of her poor health. Seiren sings on the cliffs everyday to keep all of Milka's brother's soldiers under her spell, and Milka on the island. She also tries to manipulate Milka through her dreams. After Seiren and Lilith's reconciliation, Milka goes back to her brother with Rascaless."

by Wikipedia