BOOK REVIEW: "After Dark" by Haruki Murakami

This novel is about two sisters with different personalities and point of views. One is the sleepless, college freshman little sister named Mari Asai. The other is the forever-sleeping model –and older sister – Eri Asai. The story begins a few minutes before midnight and is carried out all the way to daybreak.
Most of the story takes place with Mari as the main character. She was first “found” at a diner, reading a book by herself, just to wait for time to pass by. Coincidently, she met a young trombonist whom she had met a couple of years back. Mari has an uninterested-about-anything-that-passes-by trait that makes her an amusing character.
After that, she encountered with Kaoru. She is the manager of a love hotel called Alphaville. The story goes on as she stumbled upon more people that changed her perspective towards life and her sister. Meanwhile, the writer expressed Eri’s night to be long and cold with unwanted “eyes” watching her even in deep slumber.
Before I go on, I have to warn you all for spoilers. For those who would want to know about the ending without reading the book, leave a comment and leave now! While for those who would not mind, you may stay.
This book ends with Mari finally returning home the next morning. She even went to her sister, pleading her to “come back” from her slumber. Eri has been sleeping for a long time, but it was not a coma. She wakes up now and then to eat and the occasional visits to the lavatory. Besides that, however, nothing. She would return to her bed to sleep. Personally, I think one of the main things that the writer is trying to tell us is that no matter the indifferences between family members, blood is thicker than water. Sisters are sisters, and that is that. Nobody can change the fact of our own flesh and blood.
Do you think so?