Most of the so-called Halal restaurants in Japan are actually not halal at all. That is a pretty bold statement. I am sure most of you may not like this. Of course, you are free to think about what you would like to. However, we will talk about the painful fact as to how these so-called halal restaurants are destroying the concept of halal and actually offering haram food to their customers. They do not care about halal. Their sole aim is to earn money from their customers no matter which way it may come.
Please do not get angry with me. I have been living and working in Japan for the last 23 years. I have seen over the years that whenever I wanted to go to a restaurant to have lunch or dinner, many of these restaurants would try to offer me non-halal meat in the guise of vegetables. I am especially concerned about the halal authenticity of the restaurants which are owned by non-Muslim foreigners (not Japanese). These so-called halal restaurants try to sell sub-standard haram dishes in the name of halal. Most of their employees are also non-Muslims. For them, halal is just another way of doing business and earning money and nothing more than that. They do not care what we eat. Many of these restaurant employees are not clean at all. They go to washrooms and then restart working in their kitchens without even washing their hands properly.
Let me give you an example of what I am trying to say about the authenticity of their halalness. Long-time ago, I went to an Indian/Nepali restaurant in Nagoya and told them that I wanted to eat a vegetarian dish only. I repeatedly asked them not to bring me any meat whatsoever. The waiter promised with me that he would do the same as requested. However, when I started eating I noticed that there was some meat inside the plate. I called that waiter and showed the meat he had brought to me. He simply replied that they did not have any vegetarian dishes on that day and he did not want to lose my business. So, Instead, he served me a meat dish. Unfortunately, that meat was either pork or non-halal meat purchased from a nearby supermarket. At that time I stopped eating. Now, I rarely go to any Indian/Nepali restaurant which is owned by a non-Muslim foreign owner. So you see this is the level of professional integrity these so-called halal restaurants have about their business.
Another reason these restaurants are actually not halal is that almost all of them serve wine/beer/ or alcohol or whatever you would like to call it. They do not keep wine and halal meat (even if they have one) in separate places. More often than not, they keep halal and non-heal meats in the same refrigerator. They use the same knives and cutting boards for halal as well as non-halal meat. And, believe me, they do not have any extra space in their kitchens to keep these two types of meat separate form each other.
One of the most important reasons these restaurants use non-halal meat is that it is cheaper than halal meat, is easily available at every supermarket in the country, and a majority of their customers do not care about halal meat at all as they are non-Muslims themselves. Animal oil is also extremely cheap which, in most cases, is extracted from pork.
Still another tactic they increasingly use to trick their Muslim customers is that they always keep a few packets of halal meat and chicken in their refrigerators in case a Muslim customer asks them to verify whether they were serving halal meat.
The reasons I do not go to these restaurants are quite a few. However, you may judge on your own and you may want to verify the halalness of their offerings if you would like to eat there. There still might be a few restaurants owned by non-Muslim foreign owners which actually serve halal dishes. However, we do not have that information available yet.