From MangaHelpers:

Sakagami Tokuzou has died, leaving behind three grown children (Matsukichi, Takeko, and Umeo) and one grandchild that never knew him, Takeko's son Jin. In life, he was a carefree, happy-living man that constantly frustrated his children, and he's decided that he'll be the same in death. His last words to them were to divide up the inheritance by playing darts, and to have fun.

The three re-united squabbling adult children didn't really see the humor in this, especially once they learned that there actually was an inheritance to win--100 million yen of it. As they go together through the necessary steps after their father's death, Matsukichi, Takeko, Umeo and Jin will learn much more about Tokuzou's history and life, his friends and his secrets. If they make it through all the wackiness, maybe they'll understand the legacy Tokuzou wanted to leave behind! [tethysdust]