I still love Sayu in lovesick spaz mode. She finally admitted all the grown-up attitude, becoming a model student, and other stuff was because she was trying to make herself become the perfect girlfriend for Kaname (whenever he happened to come back). Now she's all fired up to give it her all to, win or lose. I can't wait to see how badly it will going, with Kaname being kinda a dick lately, and Chisaki probably reciprocating Tsumugu's feelings (we all know it by now, even Kaname can see how well the two mesh).
Tsumugu compares Chisaki to the sea, but he is too. He's very calm on the surface, but full of inner turmoil underneath. We finally got into his thoughts as he dove into the sea, possibly for the first time ever. He was willing to let himself die to make sure he didn't lose the chance. I guess the good parts of the Sea God's emotions answered, and gave him ena.
I do feel like they glossed over the reveal about his parents. They hinted at it being a much bigger deal when he saw his mother in the city. Then they just brush it off with a few sentences.