Fukasaku

and, better known as Ma and Pa are two Toad Elders from Myobokuzan that taught Jiraiya Senjutsu in his youth.

Because he is vastly younger than them, Jiraiya speaks quite respectfully to the Toad Sages, while they refer to him as "Jiraiya-chan" or "Kiddo". During the flashback of Jiraiya's visit to the Great Toad Sage, it is seen that both of them sit on each side of the Toad Sage. Shima seems to constantly bicker with the Toad Sage for being senile, while Fukasaku seems to advise him, and just try to help him out.

Shima and Fukasaku are summoned by Jiraiya to provide the help he needs whenever he needs to enter 'Sage Mode'.

Personality
Both toads are considered old and wise and are greatly respected by all who know them well enough. However, in reality, and to those that know them personally, it would seem that they are both acting towards each other like an old married couple, (like they are,) and constantly bicker over all the small things while they should take focus on the bigger picture, as seen when they were summoned and Shima began complaining about the fact that they were going to be there all night and 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, and at the same time does not have enough respect for the oldest and greatest of all toads, constantly calling him senile for constantly forgetting everything.

Though they constantly bicker, it seems like they truly love each other, as evidenced by Shima's emotional reaction to Fukasaku's death at the hands of Pain; later she is seen cradling him.

Hunt for Uchiha arc
When Jiraiya began to lose his battle with Pain, he called the aid of Shima and Fukasaku to help him. With the two toads he transformed into his Sage Mode and began to battle the three bodies of Pain on seemingly equal terms. Unfortunately after the Toad Sages used their Genjutsu and Jiraiya killed the three bodies, Pain's remaining three bodies arrived and turned the tables in the battle.

After Jiraiya managed to kill one of the bodies, he had Shima take the body back to Konoha so Tsunade could study it. After she left, the battle took a tragic turn as Jiraiya was attacked by the five remaining bodies, being pierced right through his back by five pike like weapons. Jiraiya knowing his end was near, carved an encrypted message onto Fukasaku's back allowing him to escape, while Jiraiya succumbed to his injuries.

Later after the 8-Man Squad failed their mission to find Itachi or Sasuke, Fukasaku remained in Konoha to inform his student's apprentice, Naruto Uzumaki, that Jiraiya died in battle. He apparently has taken a liking to Naruto and hopes he really is the "Prophesized One" who would save, not destroy the world. Fukasaku offered to train Naruto in the sage arts, so that the boy could stand a chance against Pain, and Naruto readily accepted.

Senjutsu Training
After Naruto got ready to go, Fukasaku took out the Toad Summoning scroll, which was easily recognized by Naruto. The two then traveled to Myobokuzan through a reverse summon by Gamakichi. Fukasaku then teaches Naruto about sage chakra. To learn sage techniques, you have to become one with nature. After Naruto asks how to do that, Gamakichi tells him he has to die.

Fukasaku tells Gamakichi to stop it and after telling Naruto that he doesn't have to die, he leads them to a waterfall which will make Naruto's training easier. The waterfall is filled with toad oil from the Myobokuzan Mountain. He puts some on Naruto's hand and explains that the oil will help him use natural energy. He then explains that if you don't use enough natural energy it won't work. And if you use too much natural energy, you'll turn into a frog. Since Naruto is using too much energy, he turns into a frog, which he panics about.

After Naruto turns back to normal (with a hit from Fukasaku's staff), Fukasaku tells him that not even Jiraiya could completely control the natural energy, and would partially turn into a frog. He then reveals that all the stone frog statues behind them are the past failures who couldn't control the energy. Naruto says his way will be like the "Pervy Sage's" (Jiraiya) and that he won't give up. Fukasaku is glad to hear it.

As the training continues, Naruto is still having a lot of difficulties. He suggests to use the Shadow Clone jutsu to advance the progress. However, Fukasaku warns him if one of his clones completely transform into a frog; there will be no reversal.

After Naruto gets a little natural energy, Fukasaku tells him to lift the stone frog statue with his normal chakra, but the stone won't budge. Fukasaku tells him to lift it again with his sage chakra, and it is a success. Fukasaku then remarks that Naruto is getting the hang of this faster than Jiraiya did, but after seeing Naruto almost drop the statue says that he's more foolish than Jiraiya too.

Before Naruto tries to use Senjutsu without the oil, Fukasaku gives him Jiraiya's first book, "The Legend of the Gutsy Ninja", which gave him his name. After failing to use Senjutsu without the oil, Fukasaku tells Naruto to come with him. He leads him to some rocky mountains and tells him to balance on a cliff. He saves Naruto from falling with his tongue, reminding him to concentrate.

After Naruto achieves his Sage Mode, Fukasaku tells him the final step of Sage Training: learning the toads' fighting style. After Naruto finished learning the toad's fighting style, Fukasaku tells him the final step is to merge together. Which totally freaks Naruto out (he doesn't want to look like a toad). Fukasaku then explains it's only him sitting on Naruto's shoulder.

Unfortunately, the process of doing so has been revealed as seemingly impossible as the Nine-Tailed Demon Fox's chakra keeps repelling Fukasaku's attempts to merge. Fukasaku and Naruto were told by unnamed toad that the messenger toad's name had gone missing from the tubes. Shima, who is out shopping nearby Konoha during Pain's attack, speculates that something is happening. Subsequently Shima, Fukasaku and Naruto plan on summoning something big, something apparently only all three of them can summon by working together.

Invasion of Pain arc
After Naruto is summoned alongside Gamaken, Gamabunta, Gamakichi, and Gamahiro, he wonders where he is but Shima tells them they are at Konoha which was mostly destroyed by Pain. He then marvels at Naruto's new found power as he begins his fight. Right as Naruto begins his fight with Pain, Fukasaku and Shima jump on Naruto's scroll as he takes on one of Pain Summons. Then Animal path summons two animals that charge at Naruto. Fukasaku and Shima then use their Sage Technique to stop the animals, which gives Naruto enough time to defeat them.

After Naruto defeats one of Pain's bodies without even touching him, Fukasaku explains with natural energy it expands his reach of his punches. Fukasaku and Shima are shocked when Naruto reveals his Wind Release: Rasenshuriken, which is a jutsu he did not see when training with Naruto. As Naruto throws it, Fukasaku is amazed that he can throw such a dense thing, and is even more surprised when it expands. Then Animal path begins her attack, the dog that Gamabunta is sitting on separates and begins to attack Gamaken, and Gamahiro.

Fukasaku then comes up with a plan, he ask Gamabunta to swallow Naruto, then Shima uses another sage technique to create a smoke screen, and Naruto defeats the Animal path inside Gamabunta's mouth. After Naruto loses his sage mode Shima tells Fukasaku that they should fuse with Naruto, but Fukasaku tells her that they can't because of the Nine-Tailed Demon Fox. Then Fukasaku summons one of Naruto's clones, so Naruto can regain sage mode.

Shima and Fukasaku attempt to perform an illusion technique on Pain to buy Naruto time, however Pain manages to prevent the illusion, impaling and murdering Fukasaku with a sword in the process. After Pain pins down Naruto with several of his chakra-transmitter blades, Shima urges him not to give up after Jiraiya and Fukasaku sacrificed their lives believing in him. Pain, annoyed by this, knocks Shima away, presumably knocking her unconscious.

After Pain and Naruto leave the village Team Guy finds Shima lying on the ground. As Sakura heals Hinata, Shima tends to a lifeless Fukasaku with a worried expression. After Nagato's death, Fukasaku is brought back to life, shocking Shima and Sakura. Later, Shima and Fukasaku are both seen together, standing atop Gamakichi's head, watching from a distance as the population of the Hidden Leaf Village welcomed Naruto back from his confrontation with Nagato/Pain.

Abilities
In battle, they are extremely formidable. Shima is shown to summon a serpent-like creature from her stomach. Shima is also capable of breathing fire. Fukasaku is shown to extend his Senjutsu chakra-filled tongue. His tongue becomes so fast and so sharp that it can cut through solid stone. Fukasaku's tongue is also capable of blowing huge gusts of wind as well.

The combination of Jiraiya's ability to spit oil, Shima's ability to breathe fire, and Fukasaku's ability to blow huge gusts of wind can create a huge inferno. However, its capabilities are unknown because the attack had never successfully struck the target. Also, they seem to be very intelligent, as they quickly determined a weakness in the way Pain uses his Rinnegan.

The two toads are also capable of using a very powerful Genjutsu technique called Demonic Illusion: Toad Confrontation Singing. This ability cancels 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 tones and harmony 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 nerves of the target(s), which will paralyze the entire body of the target(s). However, it gives Shima and Fukasaku a sore throat. This means that this technique can only be used once in battle.

Also, Shima and Fukasaku have been confirmed to be 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, blend 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 that's stronger than other types of chakra. Other benefits include an unnaturally high level of raw strength, incredible speed, and huge resistance to physical attacks.

Trivia

 * Fukasaku is one of the few characters in Naruto to experience death and be brought back to life. The others to have experienced this are Gaara, Kakashi Hatake, and Shizune.