The manga often relies on "show, don't tell." For example, we see that Kakashi Hatake is tired after using Kamui , but the databook tells us exactly why : his chakra reserve stat is a 4/5, whereas Naruto (after the Rasenshuriken training) is a 5/5. These PDFs are the missing manual to the Naruto universe.
The Fourth Databook sheds light on mundane, tragic lives, listing (mother) as a housewife and (father) as a doctor. Naruto Databook Pdf
