tight rope is a two episode movie about gangster love. It's very sweet and funny and has the same theme as sekai ichi hatousi. There is some fighting in it and sexual implication but both enhance the story.
I enjoyed the character relationship the best, I'm a romantic at heart and liked how they interacted.
Again my only complaint is how short it is, can certainly see this as a longer series but even in the two they completed a whole story that leaves you with a good feeling.