Takeo Tsurumaru  

, 鶴丸 丈夫

The character in question is one of the passengers who vanished from a plane flight that Shiina was on. She mistakenly thought he was the author of a threatening note. Despite not always knowing where his duties lay, this individual assisted Shiina and Akira multiple times throughout the series. He had a tendency to be promiscuous, fathering five illegitimate children and three girls who became pregnant during the course of the story.