During the final semester of their senior year, five high school couples grapple with the realities of becoming adults and how it impacts their relationships. Carissa plans a surprise 18th birthday party for her work-a-holic boyfriend, Brian, while Allison struggles to integrate into her boyfriend Will's social circle. Meanwhile, the rest of the Sweethearts plan for their upcoming Senior Prom.

It's almost time for senior prom, a night that each of our couples has been dreaming of. Brian faces the scrutiny of Carissa's watchful father. Meanwhile as one couple is nominated for Prom King & Queen, another is uncertain whether or not they'll be able to attend the dance at all. Also, a potential new romance begins to brew between two longtime friends.

Reeling from their prom night disappointment, Allison and Will R spend Spring Break apart. Meanwhile, tempers flare between Jenica and Will T on vacation in Florida. Meanwhile back in Charleston, Makhi tip-toes around his romantic feelings for his longtime friend, Kat.

College Decision Day has arrived, and while one couple dreads a 7 hour separation, another faces long distance with seeming confidence. Meanwhile, as one boyfriend wrestles with the decision to attend the same college as his demanding girlfriend, frustrations brew amongst other pairs when their partners procrastinate.

In the lead up to a State Championship and final exams, senioritis takes its toll on the Sweethearts. As some couples are brought closer together by change, conflicting dreams threaten to push others apart. Meanwhile, it's almost time for Kat and Makhi's long awaited first date!

The time has come for the Sweethearts to turn their tassels, but can relationships survive if one partner doesn't actually graduate? Meanwhile, Quinn and Miranda examine the unexpected consequences of attending the same college, and Kat is unsure where things stand in her budding romance with Makhi.

Reeling from unfortunate news, can an anniversary celebration bring one couple solace? Meanwhile, resentment rises in two relationships as girlfriends hold their partners to higher expectations. Later, when Quinn and Miranda embark on a summer bucket list, his dad throws a wrench into their plans.

As the Sweethearts celebrate Independence Day, Elle and Justin struggle to free themselves from her overbearing, parents' demands. Meanwhile Will T makes a gesture towards reconciling with Jenica, as their romantic evening under a fireworks turns into another fight.

Ready for one last hurrah, the Sweethearts plan a Senior Trip! While fun in the sun finds some couples relishing their final moments as Sweethearts, others are overwhelmed by the togetherness. Communication issues abound as the reality of imminent separation sets in.

As summer comes to a close, the Sweethearts say goodbye to their lives they knew. Despite degree of distance between schools, past assumptions, or even promises, each pair now recons with the pros and cons of staying together in a whole new light, knowing this decision will change everything.