Ie ni kaerou.
My grandmother was a tiny woman, so her ashes fit in the urn without much trouble. My maternal grandfather, on the other hand, was a bit tall for someone his generation. When he passed away, and the family passed the bones from one pair of chopsticks to another, and the crematorium attendant had swept everything off the gurney, the lid would not fit. So the attendant did the only thing he could do, which was take out the skull bones, pack everything down a bit, resulting in a distinctive crunching sound, and put the bones of the skull back.
After the ashes are, ahem, placed in the urn according to tradition, they are taken back to the ceremony hall. When you go back to the ceremony hall or temple, you must never go back using the same road, because the spirit of the dead might follow you back. (This presents an interesting problem in rural areas where there are a limited number of roads.) Back at the temple or ceremony hall, more prayers are offered. According to tradition, more prayers are supposed to be offered on the 7th day after death, but these days, it's so hard to get everyone together so frequently, you'll just pretend seven days have passed and offer another set of prayers at this time. After all that chanting about how life sucks is done, the family will share a meal. and then go home with the ashes, and the ashes are placed at the family alter or some other safe place. They're kept at home for 49 days, according to tradition, during which the family goes into mourning. Mourning is a relative term. You give offerings of food and sweets and whatever else the deceased liked, but you don't cover all the mirrors or dress in black or stop singing or playing the piano the entire time or anything, at least not these days, anyway. I know of a family who went skiing during their period of mourning when their dad died. They put the urn in a backpack and skiied down his favorite slope.
On the 49th day, (these days, however, it might not be exactly 49 days because the 49th day might not be on a weekend) prayers are offered again (with the same reminder that life sucks but it goes on) and the urn is placed in the family grave. The family is left with a tablet-like plaque on which the deceased's new name is carved. This plaque (ihai) is very important, and is the third thing you grab in case of a fire (after the baby and the bank book).
Graves are supposed to be visited regularly, but tradition requires visits on the 1st, 3rd, 7th and 13th anniversaries of death.