So... Terrance and Tsuki are the parents. All of the children use Tsuki's last name (Magorobi) instead of Howard, their father's. Tsuki was always sort of unwell after having the twins and when having her third and final child, she passed away (The twins were probably five or six). Terrance tried to be there but soon turned to alcohol. When his eldest children got into the entertainment business, he wanted them to be absolutely perfect, especially Teri. She still struggled with her looks until her death, never feeling adequate. Daiko hates his father, only wanting to return for Namiki, who they call Nami for short. Nami is basically your precious little sister, that's really it.
