Full Metal Panic! Invisible Victory

It may have taken 3 seasons but Souske admits that he actually has feelings, not that he understands them.

You must watch season 1 and 3 before watching this series, season 2 is optional but worth watching as a humorous side story, a fundamental understanding of arm slaves, the characters, their personalities and relationships is assumed. This chapter flows nicely with no slow parts as Souske relentlessly peruses Kaname alone and the remaining forces of Mithril struggle for survival after being decimated by Amalgam.

To me it feels like half a season, it ends on such a cliff hanger with a few loose story threads, I just can't wait to see where the story goes from here and hope the story does continue.

There are a few quite disturbing scenes in this series, not suitable for very young minds.