Janša did not speak to the press after the meeting, but his office said in a press release that the talks touched on potential for cooperation in infrastructure projects, "in particular railways and energy".
Hitachi is a leading supplier of nuclear technology and Slovenia plans to build a second reactor at its Krško Nuclear Power Plant.
Slovenia also plans to upgrade its railway network, though the project has been put on the backburner due to lack of money.
Kawamura refused to go into details of the talks, saying only that "nothing specific" was discussed.
Kawamura is in Slovenia as the chairman of the EU Japan Fest Committee, a foundation which is sponsoring several events as part of the European Capital of Culture in Maribor.
Janša was quoted as saying that cooperation in culture was positive, as it created opportunities for cooperation in other areas.
After the meeting Janša and Kawamura saw a concert by young singers from Europe and Japan, featuring among others singers from Tohoku region, which was devastated by last year's earthquake and tsunami.