- Yo-kai Watch Shadowside animation: Major antagonist (formerly)
- Yo-kai Watch 4: Minor antagonist, Boss Yo-kai, Befriending Yo-kai
As Ganryuu Shimanouchi, he is a young man with short, black hair, and half-closed, olive-colored eyes (making his face slightly resemble that of Dandoodle from the original series).
He wears a black shirt and light-colored pants. The shirt has a pocket with blue and red pens in it and an eye-like symbol underneath.
As Douketsu, he is mostly black with fiery hair with gradients of purple and violet. Between his orange eyebrows, he has a green amulet. However, this appears as an eye with a green iris and a golden sclera from time to time. He has flowing hair on his arms and a white mane of white hair on his chest, he also has a small and almost unnoticeable tail.
He wears black sack-like pants with white clouds around the bottom and is tied together by a dull gold waistband around them.
Douketsu previously wielded the Ashura Gouenmaru.
Douketsu has been shown to be extremely loyal, following Shutendoji (Shadowside) even when Shutendoji ignored his warnings about Ayame. He is also very rude, being shown to call Akinori a piglet almost every time they encounter each other.
Douketsu appears briefly in the post-credits scene of Yo-kai Watch Shadowside: The Return of the Oni King, alongside his master, Shutendoji. He notifies Shutendoji about Rasen's defeat and Shutendoji is disappointed that someone named "The Princess" didn't make an appearance. He was holding the Ashura Gouenmaru at the time.
Ganryuu Shimanouchi works as Natsume's teacher.
In SS004 it is revealed that he secretly works together with Haruya and Fukurou, looking for the one they call "princess", and in SS005 it is revealed that Ganryuu is capable of transforming into Douketsu.
In SS013, it is revealed that Douketsu currently wields one of the five Yoseiken.
In SS014, he monitors Fukurou's fight with the detective agency. After Fukurou's defeat, he attempts to retrieve the Fudou Raimeiken, but not before berating Fukurou for disobeying orders and telling him that both he and Shutendoji have lost faith in him, which results in his despair reaching rock-bottom and causing him to transform into Shinmagunjin Fukurou. He attempts to fight him, but his power is no match for the now monstrous Fukurou. After Fukurou is defeated, he is shown discussing the event with Shutendoji.
In SS030, Ganryuu's identity as Douketsu is finally revealed to the detective agency.
In SS037, he follows Shutendoji's plot to steal Touma's Yoseiken so that they can awaken The Princess before Soranaki finds her. Everything seems going according to plan until Soranaki appears and quickly defeats Douketsu and Shutendoji. During the battle, Natsume uses a mysterious power to easily defeat Soranaki.
In the aftermath, Douketsu reverts to Ganryuu and kneels before Natsume alongside Shutendoji. They claim that she is the reincarnation of The Princess that they have been looking for and will follow her orders without hesitation. Despite her refusal to work with them, Ganryuu smiles satisfied because they have finally found The Princess, thinking to himself that this is just the beginning.
In SS038, he is seen walking alongside Natsume and Haruya to the Shirayuki shrine. He and Haruya were later discussing on how Natsume temporally awoke as the princess only due to their barrier.
In SS043, he protected Natsume from victims of the Soranaki virus, only to end up infected himself. Then he battled Shutendoji under the effects of the virus, after they fought, he regained consciousness only to tell Shutendoji to kill him to remove the virus from him. Despite Shutendoji's reluctance, he used Douketsu's Youseiken, and slayed him, removing the virus, but killed him at the same time.
Yo-kai Watch 4
How to Befriend
In the post-game, you can find Haruya at the Arihoshi shrine, talking to him can make a quest begin if you choose to accept it. Once you finish the quest, Douketsu will join your team
Yo-kai Watch: Wibble Wobble
- Before Ashura was revealed, it was assumed that Douketsu was the wielder of the Ashura Gouenmaru.