I want to recommend a manga called Karakurizoshi Ayatsuri Sakon.
Artist: Obata Takeshi
Author: Marou Sharaku
It's status is incomplete, and it looks like it's going to be on a permanant hiatus, but the stories in the existing 19 chapters are real nice.
The main character is a man called Tachibana Sakon. He is a puppeteer, and when he controls a puppet, his personality takes a 180 degrees change.
Originally, he is quite an unreliable and careless person, but with a puppet under his control, he becomes a very level headed and somehow smarter person.
But in either modes, he is still a very quiet guy.
His puppet is called Ukon.
Ukon is a loudmouth puppet and talks a lot. Well, Sakon, being the puppeteer and a ventriloquist does the voice of Ukon, but when Ukon talks, it seems as if he were a totally separate person from Sakon as he sometimes makes fun of Sakon.
In addition, when Ukon talks too much, Sakon usually slaps a hand over his mouth to stop him talking, though he could just stop voicing.
When controlling Ukon, Sakon's face barely shows any emotion, and it is a running gag that in that mode, Sakon's face looks like a puppet's.
When Ukon expresses surprise, Sakon remains a nonchalant mask, though in extreme situations, he does show emotion, though more subdued than Ukon's.
It is amazing how he can continue voicing for Ukon even when he is apparently shocked.
Continuing, because of his odd job as a puppeteer, he sometimes gets wound up in odd mysteries involving murders.
Due to his levelheadedness when controlling Ukon, Sakon is able to think through the situation and come up with an answer for each mystery, revealing the muderer.
It is a really cool manga, though it's really saddenning that it hasn't been updated in over a year, so I assume it has been discontinued.
