Tactics follows the exploits of the young man with the ability to see goblins and other mythical beasts named Kantarou Ichinomiya. Ever since he was born he had the 6th sense to see the demons and others mythical creatures called “Oni”. When he was a little boy his friend Oni told him about the creature that is stronger than Oni called “Tengu”, it is the legendary demon-eating goblin. Since that story told him he dream to have a Tengu that will be his buddy forever. When he grew up he became a folklorist, who write books and article about Japanese folklore, but he also work as a monster buster secretly. In the episode “The Black Goblin Awakens”, Kantarou went to exorcise monster he was lead to a rural shrine up in the mountain where the Tengu, demon-eating goblin was sealed there. When Kantarou breaks the seal, he named the Tengu Haruka, in naming a Tengu it forces to be a slave of someone who gave name with it. As the fulfillment of Kantarou dream, Haruka became his partner in fighting the evil Oni. With his tengu and his kitsune, they solve mysteries, and help the yokai situation in Japan.
As the story progress, there's a lot of yokai case that Kantarou and Haruka faced such as the case that deals with the mystery of the missing children and the dragon god. The two new characters also introduced, namely Sugino and Mou-chan. Sugino is a handsome supernatural creature not unlike Haruka. Mou-chan is an odd choice for wife that he loves immeasurably. He has a dislike for humans and considers himself superior in every way. Sugino finds Haruka fascinating and gives him some words of warning regarding his bond to the human Kantarou.
In the episode “Dancer in the Darkness”, Kantarou together with Haruka and other friends returned to his home town to visit a childhood friend who is now a famous geisha. She expresses concerns about her latest client who has her perform the same dance during every session while a stranger watches from the shadows. Her client also happens to be a renowned doll maker who engages in questionable behavior with his latest creation. When she was called again to perform in the house of the doll maker she brought Kantarou and the gag with her because something was bothering her when she performed. Kantarou discover that there is an evil spirit in the house and they find out that it is in the doll's body. Using his kitsune and the help of Haruka they save the geisha however the fight start to burn the house. The doll maker let himself eaten by the fire together with the doll who he dream to have life.
As Haruka's past slowly comes back to him, his relationship with his master starts to crack. Haruka struggles with his past and yearns to learn of everything he had forgotten, especially the identity of the person who had sealed him within the huge rock boulders. This is the point where Minamoto Raiko and his group of soldiers come in. Together with another formidable demon, Raiko and his attendants plot many plans to try and force Kantarou to cancel the name contract or make Haruka awaken his real powers, such that they would be able to capture Haruka and present him to "that person" whose identity is unknown. If the name contract is not canceled or if the master dies, Haruka's power would forever be restrained and he would not be able to be used by the antagonists. But unfortunately those antagonist did not success in their evil mission and Haruka back in his senses and go back to Kantarou. They start again and do their usual routine such as fighting evil spirit and saving people.
