This plot for this series from 2000 bears more than a passing resemblance to the plot for his 2008 film The Magic Hour. In both, an out-of-work actor is persuaded to be something he isn't as part of some elaborate hoax. The main difference is that in The Magic Hour, the actor believes he's making a film, while in Ai Kotoba wa Yuki the actor is fully aware of his deceit.
It involves a village trying to stop a big multinational firm from ruining its countryside. But they cannot afford to get a decent lawyer. So one of them goes to Tokyo to find one who'll do it on the cheap. Unable to find that, he convinces an actor to come back to the village and tell everyone it's impossible to win such a case. But instead the actor gets carried away and instead insists they can win and he can help them!
After that, the story mostly involves trying to keep everyone in the dark while trying to find a dignified way out of the mess. It's funny and occasionally quite touching. It's remarkable that an eleven-part series which only has one storyline doesn't seem too long nor does it run out of ideas. Mitani Kouki does an excellent job of coming up with problems and solutions which don't stretch the viewer's suspension of disbelief beyond breaking point.