I'm usually fine unless my favorite characters die, particularly if they die just to be canon fodder. I also get angry if characters get killed off for a reason that does not forward the story. Like how Asuma had to die for Shikamaru to mature, I was OK, but I feel Sasuke dying would have no purpose as Naruto is maturing fine on his own.
Yamamoto had to go for the new generation to move forward, However Gin and Toshiro serve no purpose in there deaths other than to be cheap drama by killing off big characters which, as Kubo has so wonderfully proved, does a story no good at all.
It's like Dumbledore and Fred Weasley. Dumbledore had to go for Harry to become independent but Fred's death had no purpose than to build a body pile. The story was dramatic enough on its own. A good writer knows how to deliver drama without death, death is a cheap way of doing it. Unless a story has a reason for being sad and has started out down that road, no writer should leave readers with a bitter after taste to story.
That's my personal opinion anyway, not everyone agrees, which is why they will be waking up with half a jelly bean on there pillow tomorrow morning XD
I mean reading manga should be fun 
