You know the new Hasbro internert series "Hanazuki: Full of Treasures", right? Well, there is a theory that might creep some people out because of how creepy it is.
Hanazuki was actually a Japanese girl who suffered from multiple personality disorder (MPD), and the Hemkas are manifestations of herself. The story all began with Hanazuki as a normal girl picking moonflowers, and she had a pet rabbit named Hemka. Hanazuki had a strange relationship with the moon, and she prayed to it every night if it was visible. Her older sister Kiazuki was a girl who practiced ninja arts, and she tried to get Hanazuki into the training due to the Americans attacking Hiroshima in the 40s, and when Kiazuki heard her sister making weird noises, she stormed into the room and severely injured her as a result of jealously of Hanazuki's devotion to the moon.
Right after Hanazuki was beaten up and left alone, helpless, she woke up from the injury and became developed several mental difficulties. She killed both Hemka and Kiazuki, and put them into a container. Hanazuki after that killed herself, and it became the start of a new world.
As for the Little Dreamer, he is actually an orphaned baby that died during the Hiroshima bombing, and growing "Treasure Trees" is referring to the fact to get rid of her illness and making her life better again.