I don't get why he is so upset about Kisaragi, he could have let her be wounded, making her less of a hostage and kill Nyu with that sniper rifle as planned later...
That's some heavy guilt Kouta has, Kane dieing on hospital bed, but carrying the memento around stopped him from letting it a bit go.
Guess Bandor is the next villain in the story... for that slap, Nyu better turn him inside out.