Follow link below and click on the circle since it is in Japanese.
Here are the instructions:
1) Everybody has to cross the river.
2) Only 2 persons on the raft at a time
3) The father can not stay with any of the daughters without
their mother's presence
4) The mother can not stay with any of the sons without their
father's presence
5) The thief (striped shirt) can not stay with any family member if
the Policeman is not there
6) Only the Father, the Mother and the Policeman know how to
operate the raft
FYI-To move the people click on them. To move the raft click on the pole on the opposite side of the river.
Don't forget to click on the circle.
HERE IS THE LINK:
http://freeweb.siol.net/danej/riverIQGame.swf