Now, I know everyone knows how much of a Seto Koji fan I am, even if I want it or not. It seems that any movie/drama I watch, he's there. I don't do it voluntarily, it's just that he acts in good movies/dramas. He portrays Satoru Okura and his character is supposed to be a magician who, because of his parents, got into a scandal and people started to question his skills. In the end, he develops a trust issue and doesn't want to get out of his room. Now, there's also the badass looking guy, the second Okura, Takeru (Okada Yoshinori), who's the goofy one (in a way). He really made the drama so much better. His character shows that not everything is what it seems, mostly when we talk about humans. The youngest Okura member is the 12 years old Akira (played by Okayama Tomoki) who is extremely intelligent but doesn't want to get involved in the so called family whatsoever.
They all have their own life stories since they have been adopted by Shinzo. However, there are some other reasons the old man got these six boys and girl into his house and forced them, in a more subtle way, to become a family. Chisato's presence proves to be needed and the boys all gravitate around her. She helps them overcome their fears and issues and she is the one to unites them. There are also some romantic things going on at some point but I'm not giving spoilers.
Go, go and watch it. You'll find it very interesting ;)