The Will of Fire (火の意志, Hi no Ishi) is a recurring element throughout the Naruto series. It is an ideal rooting from Asura Ōtsutsuki's belief that love is the key to peace. It would eventually become the life philosophy which Hashirama founded and the Senju clan lived by, which has since been passed on to many ninja from Konohagakure as a part of their spiritual heritage. It states that the entire village is like a large family unit and every Konoha shinobi with the Will of Fire loves, believes, cherishes, and fights to protect the village, as previous generations had done before them. In Konoha, there is a sculpture of a flame in the cemetery representing this will, it has the kanji for "Hokage" (火影, literally meaning: Fire Shadow) inscribed below it. Hashirama was also depicted sitting on a throne-like chair with a similar sculpture in the background.
According to Hiruzen Sarutobi, this is what gives Konohagakure shinobi the strength to continue fighting against all odds, building willpower and strength of character. It is also symbolic of the hopes and dreams of the previous generation being passed to the next; for example, when Asuma Sarutobi was killed, his hopes and dreams were passed to Shikamaru Nara, who asked that Asuma's will would in turn be passed on to his and Kurenai's child.
This is also seen with the shinobi of the village identifying a "King" (玉, Gyoku) which is simply anything or anyone they want to protect. For Asuma and Shikamaru "King" refers to the unborn children who will inherit Konoha; and protection of the "King" is protection of the future generation. In the anime, Konohamaru Sarutobi believes that "King" are the civilians of the village that cannot fight for themselves.
- It has been noted that the Uchiha clan's Curse of Hatred (憎しみの呪い, Nikushimi no Noroi) is fated to clash against the Will of Fire, and Obito believes that Sasuke Uchiha and Naruto Uzumaki, both respectively embodying the polar ideals, are destined to fight to the death.
- Iwagakure has a similar philosophy known as the "Will of Stone" (石の意志, Ishi no Ishi).
- Some notable Uchiha have been able to transcend the limitations of their clan-thinking and held the Will of Fire philosophy such as Itachi, Shisui, and Kagami and Sarada. Obito Uchiha also held to such beliefs in his youth, and ultimately died following them. Sasuke Uchiha, who was seemingly lost to the Curse of Hatred, ended up coming to believe in this philosophy after conceding defeat to Naruto in their final clash.
- Kakashi theorised that Obito, despite succumbing to his clan's hatred, never truly lost his Will of Fire, and the two conflicting ideals were tearing him up inside. This would be proven true when Obito regained his former self against Madara, subsequently giving up his life to protect his newfound comrades.
- Although Sasuke only truly started to hold the Will of Fire after being defeated by Naruto, his previous philosophy of revolution also mixed the Will of Fire into his Curse of Hatred, as he would sacrifice any bonds he left and bear all the hatred and darkness of the entire shinobi world, which is a very dark form of the selflessness that made up the Will of Fire.
- The Will of Fire seems to be a fundamental concept to one's loyalty to Konoha, and those who reject it seems to be outright antagonistic towards the village, and in turn are held in contempt by the village:
- Orochimaru was passed over the title of Fourth Hokage due to his refusal to embody the Will of Fire, and held a grudge against the village as a result.
- Mizuki derogatorily considered the Will of Fire to be nonsense, and his act of sacrificing comrades to accomplish a mission shows his lack of loyalty to his fellow villagers.
- Naruto chapter 462, page 12
- Naruto chapter 329, page 7
- Naruto chapter 139, pages 5-6
- Naruto chapter 399, page 8
- Naruto chapter 328, page 8
- Naruto chapter 342, page 16
- Naruto: Shippūden episode 234
- Naruto chapter 462, pages 14-15
- Naruto chapter 575
- Naruto chapter 688
- Naruto chapter 698
- Naruto chapter 121, pages 6-7
- Naruto episodes 144-145