Saiki Kurumi[]
Kurumi is Kuniharu's wife, which he loves a lot. They are often seen hugging one another and using loving words. In Chapter 1, their relationship appeared to be terrible, but with Saiki Kusuo's help, they realised that they still loved one another and hence stopped quarreling.
Saiki Kusuo[]
Kusuo is Kuniharu's youngest son. He takes advantage of Kusuo's powers as an Esper and often begs the latter to teleport him to work. If Kusuo refuses, he would beg with disgusting teary faces. Although he loves his son a lot, he sometimes enjoys seeing Kusuo in misfortune as payback for the latter's disrespect towards him, as Kusuo had not paid much respect to him since he was a baby. Kuniharu had once even stated that he would have spanked Kusuo multiple times if not for the fact that he was a Psychic. Despite all this, he still loves his son as shown when he was excited to see that Kusuo had managed to find a friend.
Saiki Kusuke[]
Kusuke is Kuniharu's eldest son. Like Kusuo, Kusuke ignores Kuniharu most of the time. However, Kusuke also shows that he that he really loves his father as in his childhood he'd show off his inventions or acts to him.
Saiki Kumagoro[]
Kumagoro is Kuniharu's father-in-law. Kumagoro hates Kuniharu and often beats him up. Kuniharu fears him and tries not to burden the latter.
Onimatsu Gokuya[]
The chief editor at Kuniharu's office, Shuensha. Kuniharu is frequently seen licking the latter's shoes.
Nendou Riki[]
When Riki was first introduced by Kurumi as Kusuo's friend to him, Kuniharu was doubtful as Riki looked like a delinquent. However, he warmed up to the latter surprisingly quick after Riki flattered him by saying that his Santa suit looked very real.