Scarlet Heart: Ryeo has built a real following in the US on Rakuten Viki among viewers who want their sci-fi to think as hard as it looks. Across 1 season, the show has had time to find its rhythm and keep it. 585 people have weighed in on TMDB, and the verdict leans heavily positive. IU leads a cast that never lets the concept overwhelm the characters. There is no real reason to keep putting it off — it is right there on Rakuten Viki.

There is a reason Scarlet Heart: Ryeo keeps coming up in conversation. Scarlet Heart: Ryeo treats its concept seriously enough to follow it all the way through. A story of a 25-year-old Go Hajin who is transported back in time to the Goryeo Dynasty. She then wakes up in the body of Lady Hae Soo and finds herself amongst the ruling princes of the Wang Family. The human element stays intact thanks to IU and Lee Joon-gi, who anchor every scene. It was aired in 2016. What separates Scarlet Heart: Ryeo from lesser genre entertainment is a willingness to let the concept cost the characters something. It rarely drops the ball, and when it does, it recovers fast.

Scarlet Heart: Ryeo is satisfying on multiple levels — something to watch and something to think about after. Empress Ki is the obvious comparison, but Scarlet Heart: Ryeo earns its own place alongside it. A contained run means every episode is doing real work. Watch for IU in particular — the performance elevates the material. Satisfying on multiple levels.

Scarlet Heart: Ryeo wrapped up in 2016, created by Tong Hua — and 1 season is available to watch from start to finish. Find exactly where it's streaming below, and TV Butler Pro's free voice app makes it effortless to track your progress as you go. Just say the name, and Butler finds it instantly, tells you which service has it, and remembers exactly where you left off.