The memorandum of understanding will focus on improving the competitiveness of offshore wind sites in Japan, including floating wind projects.
However, it will also include "discussions" between the two firms about collaborations "on a variety of projects in Japan, Europe and other regions".
J-Power recently acquired a 25% stake in the Innogy-developed 860MW Triton Knoll offshore wind project in the UK, with compatriot Kepco taking a 16% stake.
It has developed around 500MW of wind capacity in Japan and Poland to-date.
In April 2018, J-Power set the target of developing 1GW of renewable energy by 2025 and is developing a 220MW offshore wind site near Kitakyushu City, in southern Japan.
Engie, meanwhile, is part of several offshore wind development consortiums in France and Germany and the UK.