Detective Kazutoshi Gotou is a middle-aged clumsy workaholic detective. He is an action over words/thinking person. He knows Yakumo from a long time ago. He considers Yakumo like family and worries about him despite how he often gets angry at Yakumo for his contrary attitude. He asks for Yakumo's help whenever there is a paranormal involvement in the case he's investigating in. Despite Gotou's rough ways he is actually very kind, he sometimes gets too involved in a case and if it does not work out right he blames himself for it.
When Yakumo was a just a kid Gotou saved him from being killed by his mother. Gotou was told my a man that a child was about to be killed (the man turned out to be Yakumo's real dad), he came to the site in time to stop Yakumo's mum from killing him.
In volume 5 of the light novel, Gotou got kidnapped by Honda Yutaka because Honda thought that Gotou knew the truth behind the Nanase family murder. Gotou went missing for majority of the volume, he was saved by Ishii.
In volume 6 of the light novel, Gotou took Nao in as his own daughter after Isshin passed away. Isshin had told him that he will leave Yakumo and Nao to Gotou if anything were to happen to him.
Secret Files - Kizuna:
Gotou first met Yakumo again in a park at night. Yakumo was sitting on a swing alone and Gotou thought he was the suspect he was chasing after. However, he did not remember or recognise who Yakumo was then but Yakumo knew who Gotou was. While working on a case, Gotou went to a vending machine to buy coffee and noticed a group of middle school kids physically attacking someone - Yakumo. Gotou saved Yakumo from being hurt any further, and because of it Yakumo's contact lens fell out revealing his red left eye, that was when Gotou finally recognised Yakumo as the child he saved years ago from being killed by his mother. From then on, they became acquainted again and Gotou would ask Yakumo for help in cases involving spiritual phenomena. Gotou is one of the few people who is not scared of Yakumo's red left eye and accepts him for who he is.