No. 6 fits perfectly

The scar on Nezumi's back is important to understand the character + he hides it

Shinobi Life
less (because they are more or less visible, but their origin is not revealed until late into the story)

Other one would be Rurouni Kenshin , the scar IS important, but again - the scar is clearly visible (you can see it clearly even on the cover, so).

I'm not really sure about Acid Town
I think there was something like that there but it might be my memory playing tricks on me