Sometime after the Tokyo Explosion incident, Hei had fought and defeated some Syndicate Contractors and had then fled with Yin to Okinawa. The two posed as newlyweds on their honeymoon, and Hei had tried to find a way out of the country. What began to bother him though was how Yin started acting on her own, including following him when he told her to stay put and arranging dinner for him at the inn. The two ended up not leaving by boat because of the ferry ticket lady’s warning about Yin getting seasick, and this led to Hei running into a woman at the hotel who looked exactly like Amber. Yin noticed this as well, and after seeing Hei talking with the woman and later feeling distant from him, Yin had made use of her observation spirit that night. Although Hei had woken up and stopped her from doing anything drastic, Yin saw enough to be able to say that the woman was not Amber but was indeed a Contractor. Yin had tried to suggest that he get out of there, however Hei had just hugged her and vowed not to leave her by herself... (thetvdb.com)