Plot must be resolved. The Hollywood formula has changed over the years to add an addendum to end the plot with the indications of a sequel. So your ending needs to be the indication of a new story or climax. Before you relive the anxiety of grammar school travesty starring at the blinking black line on your writing program or playing the shooter game your cousin left on the system two years ago in frustration it is very simple. If you know how to differentiate the two all you have to do is maintain one subplot element that is not resolved.
Comics rely on subplot of a character to plot the next story.
It has been done in television for years. The characters are defined so the plot becomes a different sector or street or people that they meet but they are the same. Unless of course one subplot or character facet brings another subplot to gleam. Comics are the the rubbing of coal to eventually or never produce a diamond a perpetual pressure. Film is the compressing of coal to a final burst of diamond.