It is not uncommon to hold a meeting with a Japanese counterpart in a restaurant. Therefore, it’s significant to know the basic etiquette when eating out in Japan. The first major thing to note is that the Japanese love to drink as it represents stress alleviation. If drinking is a problem for you, be sure to inform your host; they may try to get you to drink several times before they stop.
Furthermore, when it comes time for the bill, make an effort (even a small one will do) to pay for it. The Japanese will insist on picking up the tab, but it leaves a good impression if you try to pay anyways. Just keep in mind that it leaves the opportunity for you to pay if they ever visit your home country.
On a last note, since business is usually conducted in restaurants, it is rare that a Japanese business partner will invite you to their home. However, if that does happen, show them your immmense appreciation as their action represents a great sense of trust.