Fukasaku

, often referred to as is an elder toad over eight hundred years old that resides on Mount Myōboku. As the heirs of the Great Toad Sage, he and his wife Shima are revered as the.

Background
When Jiraiya accidentally reverse-summoned himself to Mount Myōboku, Fukasaku greeted the young shinobi and stated that the Great Toad Sage was expecting him. Some time after this, Fukasaku taught Jiraiya senjutsu.

Fukasaku was later present when the Great Toad Sage called for Jiraiya to tell him about his prophecy.

Personality
Fukasaku, like his wife Shima, is considered very wise and is greatly respected by all who know them well enough. In reality, he constantly bickers with Shima over small things when they should focus on the bigger picture, such as the fact that a battle will cause them to miss dinner. They are still close, as Shima is heartbroken after Fukasaku is killed by Pain. Though Fukasaku remains serious in even the worst situation, he and his wife will constantly find a reason to bicker with each other. He also has a tendency to call the Great Toad Sage, "senile" for constantly forgetting everything.

Fukasaku and Shima both seem fond of Naruto. Fukasaku met Naruto for the first time when he brought the news of Jiraiya's death to Konoha. He found Naruto's nickname for Jiraiya ("Pervy Sage") to be both very fitting and very funny, but observed that Naruto, as he was, would not stand a chance against Pain, and offered to take Naruto away to learn senjutsu at Mount Myōboku. After what was (for Naruto) a confusing introduction to sensing natural energy and drawing it in to blend senjutsu chakra, Fukasaku, in light of Naruto's rapid progress, believed that Naruto would surpass Jiraiya in power.

Appearance
Fukasaku is a green toad with white hair styled in somewhat of a mohawk, very thick eyebrows and a small goatee. He has been seen wearing two capes: a high-collared one and a simpler version. On his back is a message that Jiraiya left before he died regarding Pain: "the real one isn't among them"; because it was burned into his flesh, it cannot be removed.

Abilities
In battle, Fukasaku and Shima are extremely formidable. After Shima extends a serpent-like creature from her stomach to seek out the opponent, Fukasaku can quickly strike with his tongue. Both are capable of exerting powerful gusts of wind. Also, they are highly intelligent, as they quickly determined a weakness in the way Pain used his Rinnegan.

Genjutsu
Shima and Fukasaku are capable of using a very powerful genjutsu called Demonic Illusion: Toad Confrontation Chant. This ability cancelled out Jiraiya's lack of aptitude for genjutsu, making their combination much stronger. However, this genjutsu takes time. Also, in order to use this technique, both Shima and Fukasaku must adjust their voices and harmonise with each other (something neither of them seems happy about doing). When finally applied, it attacks the opponent's sense of hearing, and will completely paralyse the target(s) body. It gives Shima and Fukasaku a sore throat afterwards, meaning it cannot be used repeatedly.

Nature Transformation
Fukasaku has Wind Release, and in anime also Water Release chakra natures. He used a Wind Release technique as collabaration of ninjutsu with Shima and Jiraiya. In the anime he also uses Water Release techniques of high ranks. With one of the water techniques, it allowed him to pierce through walls and flesh by increasing the force of water through his mouth and reducing the opening of his mouth. He used this technique to cut one of Pain's summons in half.

Senjutsu
Shima and Fukasaku are extremely skilled and experienced in senjutsu, a specialised field of techniques that allows the user to sense and then gather the natural energy around a person and draw it inside them, then blending it with their own chakra to create senjutsu chakra. This natural energy-empowered state grants the practitioner a high amount of a type of chakra which is stronger than other types of chakra. Other benefits include an unnaturally high level of raw strength, incredible speed, and huge resistance to physical attacks. With it, he is able to raise a giant frog statue much heavier than himself, and even throw Gamabunta a long distance. According to Gamakichi, Fukasaku can amass large amount of natural energy with complete control in an instant. He is also a capable teacher, having taught it to Jiraya and later Naruto.

Tale of Jiraiya the Gallant
Jiraiya summoned Shima and Fukasaku during his fight with Pain to help him enter Sage Mode. In addition to sitting on his shoulders to provide him with natural energy, they gave him advice, and attacked Pain when necessary. Their combined efforts were enough to combat three of Pain's bodies on equal terms. Shima and Fukasaku then created a genjutsu that allowed them to kill the three bodies, but they were soon overwhelmed by the appearance of three more.

Knowing the battle was lost, Jiraiya had Shima take the Animal Path he had captured back to Konoha. While she did that, Fukasaku accompanied him during his final confrontation with Pain. When he discovered Pain's secret, he carved a message into Fukasaku's back, and sent him away before dying of his injuries.

Pain's Assault
Fukasaku informed Konoha and Naruto Uzumaki of Jiraiya's death, telling them what he could of Pain, and allowing them to photograph the message on his back. Knowing that Naruto wanted revenge, and that he was currently ill-prepared for a battle with Pain, Fukasaku took him to Mount Myōboku to teach him senjutsu. While Naruto practised tuning in with nature, Fukasaku beat him (and his shadow clones) with a staff to keep him from taking in too much natural energy.

Naruto rapidly progressed through the training stages, earning praise from Fukasaku for so quickly catching up to Jiraiya. Once Naruto attained Sage Mode, he taught him Frog Kata. After Naruto mastered the fighting style, Fukasaku began the final step of trying to fuse with Naruto as he had done with Jiraiya, something that proved impossible because of the Nine-Tailed Demon Fox sealed within Naruto. Worried that all his training would go to waste, Naruto tried to find a way to achieve Sage Mode without Fukasaku.

While Naruto continued trying to find an alternative, Fukasaku was informed of Kōsuke's death, indicating something was happening in Konoha. Shima, who was shopping near Konoha, also noticed that something was wrong in the village. She summoned Naruto, Fukasaku, Gamaken, Gamabunta, Gamakichi, and Gamahiro to Konoha's centre moments after Pain destroyed the village. As Naruto engaged Pain, Shima and Fukasaku provided assistance, dealing with the Animal Path's summons. They were amazed by his perfected Wind Release: Rasenshuriken, something he had not shown them during his training, but were again forced to deal with the Animal Path.

Knowing that the Animal Path must be got rid of, Shima coated the area in a dust cloud while Fukasaku threw Gamabunta at the path, giving Naruto an opportunity to finish it off. Pain was soon left with only one body, and Shima and Fukasaku tried once again to use a genjutsu to defeat it. Pain killed Fukasaku and knocks Shima away before they had a chance. Their bodies were later found and Shima, once healed, wept for Fukasaku. When Pain was defeated, and subsequently chose to revive everyone he had killed, Fukasaku was brought back to life, to Shima's shock and surprise. Later, Shima and Fukasaku were both seen together, standing atop Gamakichi's head and watching from a distance as the population of Konoha welcomed Naruto back.

Fourth Shinobi World War: Countdown
Fukasaku summoned Naruto again to Mount Myōboku from the Great Toad Sage's order. He is present during the conversation between the two. When Naruto had trouble swallowing Gerotora as part of their contract, Fukasaku kicked Gerotora to give him a boost. The elder toad then reverse-summoned Naruto back to Ramen Ichiraku.

Road to Ninja: Naruto the Movie
Fukasaku appears briefly when Jiraiya is told of a prophecy by the Great Toad Sage in the alternate universe.

Video Games
Fukasaku also appears in games where Jiraiya uses Sage Mode, such as Ultimate Ninja Heroes 3 and Ultimate Ninja Storm 2. In these games, Fukasaku also appears in one of Sage Naruto's combos.

Trivia

 * Masashi Kishimoto had several different designs for the Jiraiya character. In one such design, Jiraiya would change into an ugly but powerful form during moments of passion, such as anger or when seeing a beautiful woman. This version of Jiraiya had a married toad couple riding on his shoulders, who would periodically tell jokes. Kishimoto abandoned the idea because it was too complicated.
 * Naruto addresses him as.
 * Fukasaku's name comes from the legendary film-maker Kinji Fukasaku, best known for the WWII film Tora! Tora! Tora! and the ground-breaking yakuza film . The latter film starred the famous actor Bunta Sugawara, who gave Gamabunta his name.
 * In the anime, he stated that his favourite food is onigiri made from larvae.