Fukasaku

and, better known as Ma and Pa, are two Toad Elders from Myōbokuzan, who taught Jiraiya senjutsu in his youth. Because he was vastly younger than them, Jiraiya spoke quite respectfully to the Toad Sages, while they referred to him as "Jiraiya-chan" or "Kiddo" (Fukasaku started calling Naruto "Naruto-chan" during his senjutsu training). They are apparently attendants to the Great Toad Sage.

Personality
Both toads are considered old and wise, and are greatly respected by all who know them well enough. In reality, they constantly bicker over small things when they should focus on the bigger picture, such as the fact that a battle will cause them to miss dinner.

It would seem that only Fukasaku can remain serious in even the worst situation, while Shima will constantly find a way to bicker with Fukasaku. She, similarly, does not have enough respect for the Great Toad Sage, calling him senile for constantly forgetting everything.

Shima and Fukasaku both seem to like 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 to become a Sage Mode at Myōbokuzan. After what was (for Naruto) a confusing introduction to sensing natural energy and drawing it in to blend Sage Chakra, Fukasaku (in light of Naruto's rapid progress) believed that Naruto would surpass Jiraiya in power.

Shima was very welcoming to Naruto when he first went to Myōbokuzan to train, 'pulling out all the stops' at her and Fukasaku's home. Even though her cooking consisted of stewed bugs, Naruto still ate it (but had difficulty keeping it down). During the Battle of Konoha, after Pain had stabbed Fukasaku and pinned Naruto to the ground through his hands, Shima called to Naruto not to give up due to the fact that both Jiraya and Fukasaku had given their lives because they believed in Naruto, and, if he gave up then, she'd never forgive him, before Pain knocked her unconscious to shut her up.

Although they constantly bicker, Shima was shown to be heartbroken when Fukasaku was killed by Pain.

Hunt for Itachi arc
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.

Senjutsu Training arc
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 Myōbokuzan to teach him senjutsu. While Naruto practiced 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 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.

Invasion of Pain arc
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 center 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 gotten 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. When the prolonged fighting caused him to exit Sage Mode, Fukasaku summoned one of the shadow clones that was left behind in Myōbokuzan. Because he could not have Shima and Fukasaku gather natural energy for him, Naruto decided to have his own shadow clones do it instead. 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 from his confrontation with Nagato.

Abilities
In battle, Shima and Fukasaku are extremely formidable. Shima can extend a serpent-like creature from her stomach that can seek out the opponent, allowing Fukasaku to quickly strike with his tongue. Both are capable of exerting powerful gusts of wind, while Shima is able to breathe fire. Also, they seem to be very intelligent, as they quickly determined a weakness in the way Pain used his Rinnegan.

Senjutsu
Shima and Fukasaku are able to use senjutsu. Senjutsu is a specialized field of jutsu 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 "Sage 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.

Genjutsu Skills
The two toads are capable of using a very powerful genjutsu called Demonic Illusion: Toad Confrontation Singing. This ability canceled 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 harmonize 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 paralyze the target(s) body. It gives Shima and Fukasaku a sore throat afterwards, meaning it can only be used once.

Trivia

 * Fukasaku is one of the characters in Naruto to experience death and be brought back to life. The others to have experienced this are Gaara, Kakashi Hatake, Shizune, and the many victims of Pain's wrath on Konoha.