If it wasn't obvious (it's debatable) it is after this episode: Tsumugu has the hots for Chisaki. There's really no question about that. He's not making any aggressive moves, but he's sure not backing down when people are rude about Chisaki. Like I've said before, neither Tsumugu nor Chisaki made obvious moves because the latter still couldn't reach closure regarding her relationship with Hikari, and the former knew it.

I'm not sure if Tsumugu will start making any bold moves (50/50 I think right now), but if not then he's definitely on 'standby', ready for when Chisaki finally gets over Hikari.