OK, I've spent nearly all the morning trying to figure this one out.
The first four items in the Thomas set are listed as:
1. Thomas
2. Kenji
3. 後部バッファー = 'rear bumper'
4. ぶっ飛びブースター = Blastbooster
Assuming that item 4. is the jet/rocket wagon behind Thomas, what can item 3. be?
(Edit - added Blastbooster link)
The first four items in the Thomas set are listed as:
1. Thomas
2. Kenji
3. 後部バッファー = 'rear bumper'
4. ぶっ飛びブースター = Blastbooster
Assuming that item 4. is the jet/rocket wagon behind Thomas, what can item 3. be?
(Edit - added Blastbooster link)