Interesting admission from Tsumugu to Kaname that one of the reasons he has been holding back from pursuing Chisaki is because they other three weren't there. Now he and Chisaki can start moving forward again. He may be soon making is move after all.

Secondly, the alternate way to take his words to the dosing Chisaki, "fulfill what you lost with new things," was that he did love Manaka, but that things in suspension left him unable to come to a conclusion, and he started filling the loss with growing affection for Chisaki. It's not that he treated Chisaki as a rebound (nor she him), but that you take a longer look at other things that make have passed your notice before.