Sengoku Takeru is the father of Kakeru and the husband of Kozue.
He has red hair and wears glasses. He looks extremely similar to Kakeru.
He has a very serious personality. While he often has an angry or displeased look on his face, his bark is much worse than his bite, and he won't back anything up with actions. In many ways, he is very similar to his son, especially in terms of facial and bodily expressions. When he's riled up, he has a tendency to stress odd syllables in words. He was the student council president when he was in high school.
Takeru and Kakeru are very similar in terms of both looks and personality. They both play the online game, and often chat with each other in it. Takeru taught Kakeru, from a very young age, to be wary of the Hori family. Takeru will sometimes try to scold Kakeru, but since Takeru doesn't usually do anything, just yell, Kakeru will just shut himself inside his room.
Normally, Kozue is somewhat submissive and deferential towards Takeru, but if Takeru ever badmouths her or goes against her, she'll immediately bear her fangs and Takeru will back down. More than likely, Kozue is the one who wears the pants in their relationship.
Takeru considers Kyousuke either an enemy, or at best, a bad friend. Due to Kyousuke's involvement with the student council and Yuriko, the two of them were often together. Since Kyousuke has a very open and friendly and direct personality, this was at odds with Takeru's closed and serious personality. However, in his heart, Takeru considers Kyousuke a friend, though he would never admit it out loud. Takeru still goes over to the Hori house once in a while to have dinner with them.
In a very similar way that Kakeru and Kyouko are close friends and sometimes thought to be dating (denied by both), Takeru and Yuriko had a similar relationship. Takeru characterized their relationship as being "neither liking not hating her".