Hi Gori
Inaport has full Unicode support, and has also been deployed in Japan (SalesLogix site) using double byte char sets.
The catch is generally in the I/O - getting data into Inaport (reading from source) and getting it out (writing to target). There can be issues with how the source and target databases are setup, and also how the machine it is running on is set up.
That understood, the answer is yes it does work with double byte.
Regards
David Evans