I just binge watched all 6 episodes at once I cried two times it was when Yeon Woo meet Sa Wol and mi dan who resembles her mom, and I have a feeling that tae ha mom was also poisoned and his grandfather seems to be evil and hopefully his heart disease is just him being illusions
https://www.soompi.com/article/1639913wpp/park-hae-soo-and-kim-tae-hee-confirmed-to-star-in-american-series-butterfly
I cried two times it was when Yeon Woo meet Sa Wol and mi dan who resembles her mom, and I have a feeling that tae ha mom was also poisoned and his grandfather seems to be evil and hopefully his heart disease is just him being illusions