>I don’t understand what the substance of a grand coalition
>between the LDP and the DPJ would have been.
Several ministers from the DPJ and bartering in legislation, plus on-job-training for the DPJ for becoming a responsible political party.

>I don’t understand why Ozawa even considered it.
He does’t want to lead a bunch of amateurs if the DPJ actually do come to power. He is a politician who wants to be a player, and not a non-player just jeering the LDP from the bench. Some rumors also say that the LDP has some info on him that would destroy him if he refused. Very possible, since he is the successor of Kanemaru, one of the most corrupt LDP politicians in history.

>I don’t understand why Ozawa resigned.
He was probably dissapointed that his party would rather remain a “our-job-is-to-say-no-to-LDP” whiner party. it also seems that Ozawa thinks that the DPJ does not have the money or candidates to win the next election while the others are certain they can ride the media-backed wave to power.

>I don’t understand why the DPJ leadership begged him to come back.
They need Ozawa’s monetary resources to fund the next campaign. Other than Ozawa, Kan is the only one capable of bringing in any substancial sums.

>I don’t understand why he came back.
He couldn’t find enough people willing to jump the DPJ ship with him.