The languages that used "Bo" are extinct.
There's some confusion about the origins of the Celts and the Gaelic speaking peoples. Obviously the Celtic culture originated in an arc from Central Europe North of the Alps to Central Asia ~ that is North of the Black Sea.
The languages, though, spread further. Tocharian is an Indo-European language, and is closely related to Gaelic. These guys may have established trading posts in Japan several thousand years ago (to collect dead, wild silk worm bolls). The Chinese have recently been digging up some of their graves.
Yup. Here's one example.
Ancient European Remains Discovered In Qinghai (China)
"Ren said the tomb shape, the burial articles and the way they were put in the tomb are all typical in Eastern Han Dynasty (25-220), which proved the three westerners had lived here for a long time and were accustomed to local traditions and customs."
"Although so far, we have been not sure of the country the three Europeans came from and there might be a large number of such 'westerners' living here at the ancient time," said Ren."