The Way a Shinobi Dies (忍の死に様, Shinobi no Shinizama) is chapter 508 of the Naruto manga.
Kisame bites his own tongue in order to force himself back to consciousness and prevent Aoba Yamashiro from obtaining any information about the Akatsuki from him. He then creates a dome of water around himself preventing Guy from attacking him and summons three sharks within it. He then remembers his first meeting with Itachi and considering Itachi's words, makes his own sharks consume him before Yamato has a chance to stop him. Watching Kisame sacrifice his life, Naruto comments that there are those within the Akatsuki who act to protect their friends. Then Guy says that Kisame lived and died as a true shinobi should and that he will always remember him. Guy then retrieves a scroll filled with information that Kisame had collected and Motoi suggests they take a look at it but when they open the scroll, it turns out to be booby trapped and a dome of water surrounds them while a shark takes the scroll and runs away with it. Meanwhile, Tobi and Konan are shown confronting each other in Amegakure where Tobi asks Konan where she's hidden Nagato and the Rinnegan to which she replies that she knew he would come and that she's been waiting to finish him off. Tobi replies by saying that he will not go easy on her just because she was a former Akatsuki member.
In Kisame's flashback, when Itachi gets up he doesn't have a scratch on his forehead protector.