Naruto Chapter 420 -Battlefield Konoha" Summary

Naruto and Fukasaku are training several meters above Mt. Myouboku, apparently having used Sage Mode to amplify his jumping ability manifold. Naruto uses a kagebunshin to skillfully attack Fukasaku when suddenly- We cut to Konoha. Iruka runs through a ruined street and comes upon a wounded shinobi. Iruka attempts to help him, but God Realm appears behind Iruka. He demands the location of the Nine-Tails Jinchuuriki, but Iruka refuses to tell him. God Realm moves to strike him with his black blade, but the blade is caught by Kakashi, who has suddenly appeared, Sharingan exposed, to fight God Realm. Kakashi asks Iruka to leave the fight to him and Iruka complies, carrying the wounded Shinobi with him. God Realm performs a spinning back-kick, which Kakashi dodges, immediately countering with Earth Style: Flowing Wall Technique. A large brick wall appears bearing four bulldog faces. Pain manages to stab Kakashi in the shoulder with his black blade. Kakashi takes the chance to use Raikiri, but feels the pressure of the Rin'negan, much like Jiraiya did when he was impaled. This unnerves Kakashi, which allows Pain to dodge his lightning blade. Pain asks Kakashi the whereabouts of Naruto. Kakashi refuses as well, stepping back, and attempts to launch another Raikiri. Suddenly, a tremendous force erupts from God Realm, blasting back Kakashi and destroying his wall. Meanwhile, at Mt. Myouboku, Ma Toad tells Fukasaku and Naruto she's going out for groceries. Naruto grimaces at the thought of more toad food. Fukasaku then proceeds to explain that while Sage Mode and his combat training has been developed well, there are some risks. Sage Mode may only be used for five minutes at maximum. The body ceases to collect natural energy when in motion, thus combat is not conducive to creating sage chakra. Sage Mode takes a while to prepare, so it can only be used with companions around to guard and/or when out of combat. Naruto angrily posits that due to those risks Sage Mode is virtually unusable, and thus his training has been a waste of time. Fukasaku dismisses that notion, stating that if he merge's with Naruto's body, the risks will disappear. Naruto, mortified, imagines some sort of freakish Naruto-Fuksaku mutant hybrid. Fukasaku reassures Naruto that it's merely the connecting of Naruto's shoulder to Fukasaku's spine, making it look like Fukasaku would be sitting on Naruto's shoulder. Fukasaku states that this fusion is to allow the action of combat and the stillness of Sage Mode: one side moves while the other gathers energy. Fukasaku further explains that this is why Jiraiya needed both Fukasaku and his wife on his shoulders for Sage Mode. With a high-five between master and pupil, Fukasaku tells Naruto not to worry. Meanwhile, at the autopsy of the former Animal Realm body in Konoha, Shizune discovers the secret of the black metal which Pain uses: the metal acts as a chakra receiver and the metal in the former Animal Realm body is still receiving. Shizune rushes to go inform Tsunade. A rumbling alerts Shikamaru, Shiho, and Sakura of Pain's attack. They rush off to assist in the battle. Demon Realm's head opens, revealing a powerful canon which demolishes a building in one blast, catching the attention of Hinata, Kiba, Shino, Ino, and Chouji. Ino runs off to alert her father, who has finally managed to crack the protection in the mind of Jiraiya's Rain Village prisoner. Two shinobi tell Tsunade of Pain's attack. She recalls Fukasaku saying that Naruto is the Child of Prophecy, Jiraiya, Nawaki and Dan, and the fact that she gave Naruto her necklace. With these thoughts in mind, she gives two orders: To turn on the special emergency alarm and to call back Naruto!