Playing Ourselves

In an era where genetic enhancements have evolved into a world of super-humans, two young rival agents in training have to learn to work together while trying to beat each other to the top.
Ayana is the descendant of the man who figured out how to enhance human genetics. Kazz is the son of a close family friend, and just so happens to have a powerful enhancement that balances out Ayana's.
Due to the balance they bring to each other, the INSPA (International Service and Protection Association) decides they should be partners. Permanently.
While these two are forced to work together without ripping the other's head off, they are faced with another unexpected problem.
They are visited by their future selves looking to complete a mission they have been burdened with. During this visit, Ayana and Kazz find out that they eventually do learn to work well together, but it is too well for either of them to stomach.
In an attempt to play their older selves into going back to their time point without truly completing their mission, Ayana and Kazz have to fake a relationship to keep from committing to a real one.

How hard could it be to fool someone who has already gone through the exact same events because they are the exact same person?

It's as easy as telling yourself a lie.