Season 1 of The Heart's Shadow premiered on September 16, 2015.

Laveng is a journalist who works for a TV news station and is engaged to Kawee, the head of the special news team. Her life was going well until one day, she suffers a deadly car accident. Her spirit switches bodies with the fragile Amavasee who is suffering a heart problem and was sent to the hospital at the same time. She wakes up and is taken to Amavasee's home by her parents, where she meets Yo, Amavasee's fiance.