This movie contained the emotional payoff that the original series lacked. The first season started the story in the wrong place. K, at it's core, is a buddy and rivalry story which becomes a revenge story because of this inciting incident. We are supposed to feel this torn feeling throughout K. We are meant to think, "if only they could have continued the way they were, but they now must seek revenge no matter the cost!" The original series threw us into the revenge plot with no context, and from the perspective of an aimless, vague, and uninspiring character. What we needed was to careabout Tatara Totsuka from the start so that we were rooting for the Reds' revenge and understood their pain, and Mikoto's dilemma. This movie filled in those gaps, allowing me to cry for them, get angry on their behalf, and long for the unity the Reds' had before they were flung into such a terrible conflict. The original series should have started the story here. I highly recommend you watch this. K is really the story of Red and Blue. Yashiro is a side note as far as I'm concerned.