The story in the film follows after not more than a year has passed since the incident involving the Silver King, the Red King and the Blue King. The people of the HOMRA group have since disbanded and got off to live on their own. Anna, the mysterious little girl who used to always hang beside Suoh Mikoto aka the Red King, is depicted as our main character here. She's seen to be chased by two other mysterious looking guys who happen to be the Clansmen of the Green King. Yes, this is the first time the Green King is introduced as he did not have any part to play in the series. Yukari Mishakuji is the one serving for the Green King and is our main antagonist in the movie. He's later revealed as a former senior of Kuroh Yatogami who also was the student for Miwa Ichigen. For purposes unknown, Yukari leads the kidnapping of Anna but face off against Kuroh and Neko, who are in search for the disappeared Shiro.
The artwork for this was once again a visual masterpiece as was the case with the series. The CG effects were right on the money too. The voice actors stay the same from the series. The movies uses some of sound effects previously heard on the series with the combination of some of its original themes as well. And it was a bliss to hear the ending song done by Angela.
Honestly after watching the movie, I think "Rebirth of the King" would've been a more appropriate name rather than the one it has. Sure it does give us an insight to the never seen before Green King but that actually acts as a sub-plot giving the main role to a more sequel-like story. To fold it off, K: Missing Kings is an absolute must watch if you're a fan of the series. It's totally not a recap and has its own very interesting storyline with the addition of some new characters. The film does not have a full conclusion to the story though, as it's actually not supposed to be one. With the announcement of the new sequel to the K series to air this fall, the movie also acts like a considerably well done prologue to it which means all the more reason to watch it.
