Paddington Bear is a fictional character in children's literature. He appears in 14 books written by Michael Bond and illustrated by Peggy Fortnum and has evolved into a franchise. The illustrations show him more as a teddy bear than a real bear, in the original style of Winnie-the-Pooh.
Paddington speaks English and wears a battered hat which he refuses to part with. When found, he wore a Duffle Coat, and wellington boots. He is always polite and well-meaning (though he inflicts hard stares on those who incur his disapproval), likes marmalade sandwiches, and has an endless capacity for getting into trouble. However, he is known to "try so hard to get things right".
Why is he popular in Japan? I haven't seen much of him around, but I managed to collect all 8 characters from cappucino-coffee bottles. I believe he's ripe for mass marketing here after too much POOH-saturation (ew!)