I think Tsumugu is doing all he can with the research so Chisaki can see Hikari, just like Hikari did all he can back then so Manaka will be happy (and ultimately end up with Tsumugu). He's more subtle than Hikari, but I do think that's the case.

He loves the village, but I think the people (and Chisaki in particular) mean more to him than the physical village does. He just doesn't crumble when one of them is being taken away from him.