Tōru is an extreme masochist, and is not embarrassed about the fact, he even announces it in public places and often asks for abuse.
He has the role of checking on the Takanashi siblings and reporting their condition to their mother, who is too busy with work to see them.
It is known that he is divorced with Kazue in the most part of the series, however they got back together after realizing that it still feels best when the one who hits him is Kazue after he got punched by Inami (due to her androphobia). He stormed at Kazue's workplace with one cheek puffed that indicated just how strong he was punched and asked Kazue to get their pinnacle of relationship back together. Kazue being still so in love with him agreed to it.