I married this Dragon King instead of my sister Episode 5
Episode: 5
Episode 5 recap: The Seven-Day Count
Seraphina swears Isolde to secrecy, warning her that Cassian must know nothing until the wedding day. Thinking Isolde is doomed to the dragons, Cassian dotes on her constantly. He plays a tune on a porcelain ocarina for Isolde in the courtyard pavilion during the rain. Seraphina watches from under an umbrella, heartbroken. Young Cassian once learned that song from Seraphina's mother, promising to play it only to stop Seraphina's tears. Cassian now claims he plays it for the one who matters most. Seraphina counts down seven days until her departure.