Childhood friends and sworn enemies.
Liao Zhouzhou and Gu Han have been fighting since they were kids. They have to compete over everything, and even when they're drunk and end up in bed together, Liao Zhouzhou struggles to sit up and declares, "I'm going to be the top."
Gu Han holds his waist and coaxes him. "Sure, you're the top."
Liao Zhouzhou is being bounced around so much he can barely get his words out, yet he still thinks being on top makes him the top.
The next morning, Liao Zhouzhou wakes up and waves it all off, saying they should pretend nothing happened.
Gu Han refuses.
He chases after his sweetheart every step of the way, coaxing him along.
At last, he manages to shed the sworn-enemy label. With their families settling on a wedding date, it looks like he's finally about to make things official.
Then, on the night before they go register their marriage, Liao Zhouzhou throws a bachelor party, gets drunk, slips, and hits his head on the floor.
Just like that, he loses his memory.
When he wakes up, he thinks he's eighteen again, right in the middle of his heated rivalry with Gu Han.
Gu Han: Great. All that effort for nothing.
Guess I have to start courting him all over again.
"Bonus scene"
Liao Zhouzhou has been so annoyed lately.
His sworn enemy is acting like he's lost his mind. He's stopped being sarcastic and no longer picks fights with him. He keeps staring at Liao Zhouzhou, and at night he shamelessly knocks on his door over and over, saying he's his husband and insisting they sleep together.
But when Liao Zhouzhou asks him for their marriage certificate, he can't produce one.
Yeah, right.
Who knows what kind of trick Gu Han is trying to pull this time?
"Bonus scene"
Gu Han is drowning his sorrows at a bar.
His good buddy tries to cheer him up. "Don't be sad, man. I know you're in a rough spot, but look on the bright side..."
His good buddy thinks for ages, but can't come up with a single bright side.
Gu Han downs one drink after another. "Do you think this is easy for me? I've been chasing him for years, and now I'm right back where I started! These days, he even avoids me whenever I want to see him!"
He slams his glass down. "I'm done chasing him!"
He talks tough, but a few minutes later, Gu Han takes out his phone and slurs, "It's time. My wife has been playing that farming game lately. I'll call and remind him to harvest his crops."
"..."
Theme: Love is eternal