Finding a house is always a challenge.
Few things you should consider before starting to look your new home are
What is your budget
What area do you want to live
If you have kids, the school level of the area
Do you want to live in a house or an apartment
Once you have these things set, you can start looking for your house in below of these sites.
Now, you can also find cheap housing especially for sub-lease in Craiglist, but because there are some fraud cases, we do not recommend this unless you know what you are doing.
Other options if you are a Japanese is to use agencies. They would usually charge you 1 month rent for any contracts made, but they will do the searches for you.