you buy it in store.
he is at the sumo match
the sumo match is in the poptropica store go there and get it when you play then one women will be standing click on her and teel start
funnn
The island that has sumo-wrestling in it is the Red Dragon.
You don't have to open it. It is open already, and you could just go in.
The champion sumo (Yokozuna) is inside the sumo match place.
yu fx the bridge
he is the person who gives you the haiku
Once you have it, you can just go in.
The match starts after you find the suspect in the dragon, then after you fix the bridge and get the bonsai tree trimmers, and after you trim the bonsai tree.
For red dragon, help everyone else. This includes the kappa and fixing the bridge and bonsai trimming. Then go to the sumo match.
There is no "Sumo Island." The island that features ancient Japan and a sumo challenge is Red Dragon Island. (see the related question)