Who do I contact regarding rights licenses of specific manga/anime characters? My company runs a card game in Europe, but we want to start including manga and anime characters. How would we start going about obtaining licences?

We want Akira, Fist of the North Star, Ako, Tank Police, Appleseed, etc.

It's just one image character per card. Does anyone have any details on doing this legally and respectfully, with links, etc?
We can't really help you with the process licensing (since we have no expertise on it, so it's off topic), but we can tell you who the primary IP holder are for their respective media. 

Akira, Kodansha

Fist of the North Star, Shueisha

Project A-ko, Seishinsha, A.P.P.P.

Tank Police, Hakusensha

Appleseed, Kodansha

Essentially you'll have to contact the IP holder directly to work things out. You might be able to contact your local license holder to get the contact information of the IP holder. Additionally, if you can reach out to the series creators, they can better refer you to the right person.