I read one time travel romance Manhwa, where they shown first initially FL gone through time travel to save ML from dying. Later chapter Plot twist happened in past where ML already gone to past to Save FL from dying. After few chapter both main leads knows the situation.
1 
Mostly ML(Ryeoun)
Ryeoun also acted in double character in TW (mostly reveal in 15th ep)
And also waiting MDL cast section
Ryeoun- Ha Eun Gyeol | On Ji hwan
What if one of main leads already gone to past.
If my theory is possible, SML is first person will know FL from future.
where they shown first initially FL gone through time travel to save ML from dying.
Later chapter Plot twist happened in past where ML already gone to past to Save FL from dying.
After few chapter both main leads knows the situation.
Any reason