That investor was spot on. The best signal you can get from a Japanese business partner is their eagerness to go out for a night on the town :)

In Japanese, "We will consider it" or "kentou shimasu" (検討します) literally means to investigate and attack from its Chinese roots and is a way to signal distance.

If you are in early stage talks and if they are serious you will get a request to sign an NDA or some form of binding contract.