I think there are other ways to read it. We know very little about what ancient 'Jews' did or believed. The Jewish and Protestant Old Testament comes from a version edited during the Babylonian Exile about 600BC, the Orthodox and Catholic one from an older version translated into Greek about 250BC. What does that tell us about actual Hebrew practices?
What does the Bible tell us about Christianity as practised in the Vatican or in a Nigerian Pentacostal church? Something it tells us repeatedly is that Hebrews were forever getting up to no good in high places worshiping Asherah, Ba`al and Tanith as well as Yehowah. What we have in the Bible is probably what the priests of Yehowah wanted everybody to have fixed on their Temple but no closer to real folk beliefs than a sermon by John Knox to a Catholic peasant's faith in Holy Water, Relics, and prayers to Saint Theresa to have a word in Mary's ear to ask her Son to put in a good word with his Father - in other words could as easily be the Chinese Heavenly Burocracy.
We know other things though. We know that Christianity had spread throughout most of Europe and large parts of North Africa, West Asia, Pakistan and parts of India before Islam over-ran much of it by 700CE. We know that the Roman Empire had Jews in all major cities and they were in most before Rome conquered them. If they went West it's reasonable to assume that others settled East. More reasonable in fact. Zarathustrianism (Zoroastrianism) is the only religion not denounced in the Bible. Christians borrowed a lot of symbology from its offshoot Mithraism with a similar relationship as Christians to Jews. Cyrus the Great, who sent the Jewish exiles home was a Zarathustrian. The Dead Sea Scrolls, Christian, Samaritan and fringe Zarathustrian writings share a lot they do not with anything else known from the time. In Roman times, kings like the Herods generally preferred their Eastern Power Bloc to Rome. (By that time the Parthians from Afghanistan-Pakistan had over-run the Iranian Persians)
We know how Jews spread in the West. In fact they always had very close relations with Egypt - Pharoah had a Jewish regiment and before Cyrus, the kingdoms usually looked to Egyptian protection from Eastern attackers - something else the Bible does not lead us to expect. Christians spread too. We can say that Christians proselytise and Jews do not but that is now after Christians forbade Jewish proselytisation. They wouldn't forbid it if it wasn't happening! And 'Acts' is full of 'God-fearers', Gentiles who attended Synagogue and kept Jewish tabus. Few men were circumcised because apart from painful, in those days it was appallingly dangerous and regarded much as many moderns regard genital piercings and tattooes.
So - call them Israelites because they are too early for Jews and the natives of 'Israel' (including Samaritans and Galileeans) had a name in later 'Judea' for heresy - had all that time and twice as long to spread East and (apart from Egypt) far more reason to do so. Civilisation lay East, trade lay East. The chances that Israelites settled East and that many of them were not at all as strict about their religion as the priestly Bible editors would have liked is as high as might as well be near-certainty.
That does not mean they went to Japan. It does mean they may have influenced other peoples just as Christian missionaries inspired the hats Tibetan monks wear. Religion was much more fluid in the past than today, seen more as a practicality based around a central belief, much as it still can be in parts of Africa and some Buddhist countries happy to ordain trees as monks to stop them from being cut down.
We'd need to know where the Japanese came from. The language has been described as Central Asian with a Polynesian accent but a language only written in the last thousand years and then most of it non-phonetic Chinese ideograms does not give many clues. Nor does Japanese mythology - though it bears some loose similarity to Polynesian. Japanese legendary prehistory starts about 600CE. Is that when settlers arrived? If so, why no legends of settlement? England is much the same, though it has Roman history and a history of settlement with only a century or two of legend around 'Arthur' and 'Vortigern'.
The Japanese must have arrived from the South, so by boat, because they only annexed the Northern islands in the 19th century. Yet if there's one thing to be said about Polynesians, they must be about the greatest sailors of all time. The Japanese live on islands requiring marine connection - and have all the maritime tradition of a camel. They share some similarities because of their location with the British but that is the one they most certainly do not share. (Probably because Britain could always cross the sea to some country it was not at war with and Japan could only cross to Korea or China and more China)
There is a possibility without any support whatsoever that the Japanese originated as ancient Chinese deportees, some rebellious Asiatic tribe, and later gained a strong Polynesian influx. It's possible (Thor Heyerdahl thought so) that the Polynesians got to the central Pacific without leaving any traces in intervening Melanesia and Indonesia by following the Japan current up to Vancouver (where they chare cultural similarities with the Kwakiutl) and then South to Hawai'i and ultimately New Zealand. In that case, the Japanese would be very early 'Polynesians' mixed with Central Asians and the 'real' Polynesians set off from either side of Puget Sound.
All these things are possible. What is also possible is that many things Jews have preserved were once very widespread and spread to Japan as well via some trek while the pre-Japanese were still in Asia, where cut off geographically, they continued as cut off culturally they did among Jews. There are South African tribes with remarkable similarities to Jewish custom and in the reverse, the Ethiopian Falasha who claim to be Jews and have been airlifted to Israel but lack everything 'Jewish' since and including the Exodus (and are as black as any other Ethiopian). Presumably they went the other way when that happened!
Enough language similarities for the same thing can add up but it is always dangerous to base too much on language. The Latin Deus and Greek T'eos (modern Theos) are not as related as they look. The archeologist who exclaimed "This is pure Greek" when discovering that the Aztecs called their ziggurats Teocalli - God-House - because it is so close to the Greek T'eo-kallia meaning exactly the same was either jumping to conclusions or finding some ancient contact we know nothing of. But either way, that does not show no more connection between Aztec and Greek religion than Conquistadores found in Quetzalcoatl's cross and another god they identified as St. Bernard. The Cross, Swastika, Crossed Circle are all universal symbols, usually representing the Sun.
We have widespread religions like Christianity and Islam and Buddhism as well as 'national' ones like Judaeism and Hinduism and for that matter Shinto. I think it possible that even though all the religions of the past may look very different to us, there may well have been practices and general beliefs that the all shared. There certainly was not the feeling that Romans and Greeks had different religions though they saw their deities differently. Probably they did not feel Egyptian or Hindu as much different religion as different sects of Religion. If that's the case then we should expect a lot to be shared because its origin is human and different versions have borrowed and reborrowed off of each other.