Some introduction text was revealed in a Japanese game news site (http://www.itmedia.co.jp/games/articles ... ws003.html
Here is the translation.
In a dark study, a book is opened.
Within, the following is written--
"This is the record of a certain "organism"
used as a runic weapon.
This unnatural life not from this world
was imbued with runic magic;
powers that are a foundation to this world.
For that reason, this organism was used
by mankind as a weapon.
People were terrified by the evil powers of
these runic weapons, but eventually people
stood up to rid the world of these weapons.
Lets start from an incident that happened seven years
before the war between the Island Nations and the
Kooluk Empire, in the back streets of a small port town."
This intro confirms that Rhapsodia will be spanning more than a few years.
We already know that some part of this game will take place after Suikoden 4's plotline, but things that happened before Suikoden 4 will also be mentioned. This means there is a very good chance that quite a few loose ends will be tied in this game.