Gennosuke is the grand son of Kouga Danjou, the leader of Kouga and after his grand father dies he becomes the next leader. He among with Oboro are the main characters of this series. Gennosuke is probably the most powerful character in the series. All of the Kouga respect him (even Tenzen of the Iga seems to respect him too) and all of the Iga are afraid of him. He has the ability to mimic any technique used against him and when he uses this ability he seems to be impossible to be confronted in battle.
Gennosuke is not only the most powerful character but he is also the most gentle and honourable. He tries really hard to make peace with the Iga because of his love with Oboro and in order to doing that he goes to Iga village only with Jousuke. He also seems to be forgiving when he forgives Jingorou who tried to kill him.