Here are some Isuzu Erga Duo artics operating in Tokyo and Yokohama taken on a recent visit.
Keisei Bus operate four on the Tokyo BRT routes. Calling the four routes that pass through Shimbashi a BRT is a big call with frequencies of 10-20 mins all day.
They get really heavy loading but the artics seem to appear on the most frequent route that doesn't get hammered as much (due to its 5 minute headway in the AM peak).
Alongside these artics are a mixture of Toyota Sora Hydrogen buses and diesel Isuzu Erga's.
The City of Yokohama also operate three artics on the Bayside Blue route. There is some confusion if these are actually Isuzu or Hino engines in them but the rest of the bus is the same under the J-Bus venture.
Hino and Isuzu were previously both controlled by Toyota, but the latter has since been spun off and now owns UD, which previously was part of Volvo Group and supplied the engine block used for the D8K found in the B8RLE.