Takeya's stepmother, and one of the few people who can keep the rambunctious Natsuki in line; she taught Natsuki all of the techniques that she uses to beat her big brother up with, or so it appears. It is also implied that Takeya and Harumi could have fallen in love but before Takeya can say these words Harumi sticks a cherry tomato in his mouth and says "it doesn't matter now I am your mother".(Another indication was when Takeya turned to Neneko in panic as Ren was prepared to leave the Earth, she stated that Harumi dumped him) Harumi is a truly funny character with her own "personal attacks", such as the "Harumi-driver".