Saeko and Takashi are friends, but their relationship is a bit complicated. Takashi is physically attracted to Saeko and has some level of romantic feelings for her, while Saeko seems to like Takashi a little more than he likes her, though her feelings are more of a deep admiration. She respects and admires him as the leader of the group. Takashi still seems to see Rei as his primary love interest. As far as we know, Takashi and Saeko have not had any type of romantic encounter or directly addressed whatever romantic feelings they may have for each other.