This doesn't sound like the kind of blogpost a missionary in Japan should be writing.
And I want to put a big caveat up front: God calls his people to serve him in different ways and I don't intend to deny or to question anyone's particular calling or vision for ministry. In this post I'll be making generalisations. Of course, they're still true... but only generally speaking.
With that out the way, here's the headline -- if you want to reach Japanese people with the gospel (and you're not Japanese yourself) you should probably stay where you are.
Why do I say that? Two reasons, based on my experience.
1. You're more likely to have a fruitful ministry of evangelism among Japanese outside Japan than in Japan itself.
Anecdotal evidence -- and solid missionary experience -- bear this out. Stats which I've seen shared by missionaries and diaspora workers indicate that a Japanese person is perhaps thirty times more likely to become a Christian outside Japan than inside Japan. That's not just because they're more likely to meet a Christian who will share the gospel with them or to come in contact with a healthy and vital church (although these things are also true). It's because Japanese who travel overseas usually have more time, and are typically more open to considering new ideas and approaches to life than those who stay at home.
My wife and I spent five years doing evangelistic ministry among Japanese in Oxford, England, and a total of seven years in other British cities when we actively tried to meet Japanese and share the gospel with them. In these contexts, we found it comparatively easy to start up conversations with Japanese people, to build relationships, and to invite them to church or Bible studies. None of that felt "weird." In God's grace, we never struggled to find at least some people who were spiritually interested. There was a steady trickle of conversions.
That's not been our experience in Japan. Over seven years living in Japan together, we've found evangelism to be much more of a struggle here (even for my wife, who is Japanese). People are too busy. People are less open. Not for nothing is Japan one of the countries to have the dubious distinction of being known as the "missionaries' graveyard."
Of course there are exceptions. Some evangelistic ministries flourish here: praise God! Some missionaries are uniquely gifted. But the exceptions prove the same rule that our experience also underlines: if you want to reach unreached Japanese people with the gospel, you're probably better off staying at home than coming here.
2. In the long term, you may have less influence in Japan than you might hope for.
Foreign nationals and their ideas have always had a complex and nuanced reception in Japan. Since the Meiji Restoration in the mid-19th century, Japan officially followed a policy of intentional adoption of western ways. But this "adoption" has never been wholesale: it has always come together with "adaptation" to the Japanese way, according to the principle of Wakonyōsai. This means "Japanese spirit -- Western techniques." For me, it sums up the way that Japanese typically receive what foreigners seek to share with them.
Missionaries in Japan are often frustrated at the way things work, or don't work, according to their expectations. Their ideas are, apparently, patiently considered, and then gently shelved.
The reason for this is that missionary "ways" are, usually, "foreign" ways. Typically, Japanese people -- including Japanese Christians -- regard them with at least a degree of suspicion. Japanese churches are culturally very different from most western churches (or even Korean churches, although there are certain similarities). Foreign ideas may get a polite hearing in such contexts, but if they don't suit, they can be written off as just that, "foreign."
It may come as a shock to some, but missionaries are not always welcomed by Japanese church leaders. They are, in some cases, thought to be less qualified and even less committed than Japanese leaders. They are, in all cases, less culturally-attuned than their Japanese counterparts.
All of this means that ministry in Japan can feel like wading through treacle at times. Of course, it's possible to put yourself in an English-only (or Korean-only) bubble, and avoid any of the kinds of issues I'm talking about here. Or it's possible to ride roughshod over whatever anyone else thinks and plough on with your own plans regardless. But if that's your intention, you should surely question whether coming to Japan as a missionary is the right thing for you.
So, there we go: two reasons why you shouldn't come to Japan as a missionary.
That's not the end of the story, though. Watch this space for some reasons why, even given everything I've said above, you should come!