Kumagoro Saiki is the husband of Saiki Kumi, the father of Kurumi, the father-in-law of Saiki Kuniharu and grandfather of Saiki Kusuo and Saiki Kusuke. Kumagoro is a grumpy old man who hates Kusuo's father Kuniharu and loves his daughter Kurumi. He is actually a tsundere who truly wants to dote on his grandchildren.