The Real Estate business is definitely the area for which you need your Japanese legal adviser. In Japan, licensed Japanese lawyers, bengoshi, are the best advisers because only bengoshi can negotiate on your behalf with your counter parties, which are buyers and sellers as the case may be.
In addition, legal information of each property or real estate is important to know the value of it. For example you need to know the lease status of the building you are buying.
If the lessors must buy back the interior, for example, such obligations must effect the value of the building for future buyers since the buyers will assume such obligations. Sometimes arrangements about the key money are also important aspects of the property under Japanese law.
As to the purchase agreement, the timing of payment and registration is very important and foreign buyers must make sure that the transfer registration should be completed upon payment. If the payment is to be made by installments, some arrangements under Japanese law must be considered to secure the future registration of the property which the buyer is acquiring. If somebody else completes the registration of transfer of the property before you do so, you cannot obtain the owner's status of the property even if you have paid the price.