Shirasu Kinjou (金城 白子, Kinjō Shirasu), whose real name is Kotarou Fuuma (風魔 小太郎, Fūma Kotarō), is a character of the Donten ni Warau series. He is the Kumo family housekeeper and Tenka's close friend and confidante. He is a former ninja of the Fuuma clan and its 10th generation head.
He is one of the few remaining Fuuma after the Fuuma Clan was killed off. Shirasu told Nishiki that he is uninterested in reviving the clan but in reality he was planning to revive them. It was later revealed that the Fuuma clan was never killed off, those who are killed are people who are against the resurrection of the Orochi. Together with his twin brother, they let out the rumour that the Fuuma Clan had been wiped out and then proceeded to murder Kumo Taiko, while Kumo Koyuki's death was unpremeditated. Shirasu revealed that Kumo Taiko was tricky as he seems to have figured out the connection between the Fuuma Clan and the Orochi. Due to the death of Kumo Taiko and Kumo Koyuki, he was able to conceal himself within the Kumo household. Despite Shirasu's initial goal of discovering the Orochi's vessel and waiting for its resurrection, he gradually cared for the Kumo brothers as he became apart of their family.
Shirasu has wavy, medium-length white hair and purple eyes which people can easily identify him as a Fuuma. Shirasu wears a purple hakama under a white kimono around the Cloud Shrine, and pulls his hair back with a purple hairband. While out on a mission, Shirasu switches into ninja-like clothing.
While residing at the Kumo household, Shirasu is calm, polite, and quite mysterious. Raised as a ninja, Shirasu is also very loyal.
To Kotarou: "Since my rite of passage, Mother has not smiled at me even once."
To himself: “I, yearning for Mother’s love, and my brother, yearning to be a Fuuma, fulfill each other’s wishes. The two of us are one.”
To his friends from the Fuuma village: “There will be no more rites when I become Head.”
To himself: “My brother, mother, and everyone else can live happily in the world I will create.”
To his friends from the Fuuma village: “I will create the era of ninjas again.”
To Soramaru: "Today isn't over yet."
To Botan: “I don’t know what Tenka might have said, but I can’t trust you. You don’t have the scent of a ‘person’. My body odor is quite faint, but you have no scent at all. What are you?”
To Botan: “If you want to harbour such doubts, that is your choice. I’m used to this kind of treatment.”
To Botan: “If you dare raise a hand against the three Kumo siblings, I’ll see to your death.”
To Botan: “I was taught to doubt people. And taught to distrust everything. You might say that those here only know how to trust. What those three people won’t doubt…I’ll doubt on their behalf.”
To himself and Soramaru: "To ninjas, freedom is simply hell. They can only obey and follow orders."
To Tenka: "Tenka... I can't fill in for you after all."
To Tenka (after attacking Botan): "Sorry, Tenka."
To Kotarou: “I once thought it was stupid to have two heads, but it’s not bad after all.”
To the Fuuma Clan: “Listen, Fuuma. This is the time to display our power. We will not cower in the shadows of history any longer. We will catch hold of this era, and take it back!” To himself: "I am fake.."
To Tenka: "This is my answer, Tenka. Just as you have a home, so do I. So long as I live, the Fuuma will never die. Forever. Farewell."
To himself (regarding Kotarou): “Considering it, he must have been troubled all that time…in a dark cell, wondering if he’d been abandoned…”
To himself (referring to the Kumo brothers): "I was not wrong...but, Fuuma Kotarou's mistake was meeting those people."
To himself: "I am the half-haired one."
To himself (referring to the Fuuma clan): "They were all still out there waiting for an order."
To the remaining Fuuma ninjas: "Thank you for being alive."
To Kotarou: "You're with me too... You are me."
To himself: "I'll probably never smile again. My smile remains at that shrine, along with Kinjou Shirasu."
To himself (regarding his life at the shrine): "What a warm, wonderful dream."
- Shirasu is terrible at cooking. On the day of Tenka's birthday, Shirasu made additional food along with his snacks. His "food" had its goo leaking out of the house, which allowed Chuutaro to swim in the food pool, and made Soramaru very frustrated at the amount of cleaning he would have to do.
- In the drama CD, Tenka asked Shirasu what his happiness is. Shirasu replied that his happiness is having a place to go home to.
- According to Kotarou Fuuma, Shirasu does not sleep at night.