Kade asked if the diary was Kosa Ban's writing and Date said no, it was his. Kosa Ban's recording of the events is the official report given to the king. Date told Kade that the diary was an outlet for him to pour out what's in his heart or else his heart would burst lol. Date is so cheesy, he's like the king of Velveeta.
I love the difference in relationship between between Reungrit/Kade and Date/Kade even though Reungrit is the reincarnation of Date. Their love story is truly sweet too, since they started out as best friends. And Kade never forgot Reungrit and wanted to share every experience she had in Ayuthaya with him. Which technically she did lol, just a different form of him. Even last episode when they were about to go on the horse ride, she mentioned him.
And someone asked this yesterday? but I didn't want to comment cause it was still spoilery. The scene towards the beginning when Kade is standing outside the temple with Pin and Yam and she asked, "Will I ever see you again Reungrit?" and it showed a monk walking inside the temple yard is Reungrit. But unless you knew what was coming, not sure how many people would've picked up on that. I love the small details like that in here.