Yes this has not been implemented yet. And I think it won't be for a while longer (though it is really hard to tell anything about future content, as this game surprisingly has no player created log of all the upcoming updates, very strange)

Anyhow, the system is not related to your friends bond, so do not worry about that, it's stating that you need to increase your bond with visiting ninjas, and that's exactly what it will require. Some time in the future, when it finally arrives, you'll have ninjas come over to your place, and you'll be able to give them gifts, and they will give you quests and other rewards.