"The Heart Stone" (心の石, Kokoro no Ishi) is episode 85 of the Boruto: Naruto Next Generations anime.
Boruto is frustrated with being stuck in the Sanzu Plains, while Ōnoki reiterates they can only leave if he finds his Heart Stone, which Ōnoki finds unlikely, since Boruto entered the plains by accident instead of with the intent to train. While walking through the plains, Boruto stumbles across Sekki, an Iwagakure genin who failed out early in the last Chūnin Exams. Ōnoki asks what he's doing there, and Sekki explains he's been looking for his Heart Stone. Sekki asks what Boruto is doing there with Ōnoki, but before he can explain Ōnoki's machinations, he assumes Ōnoki did something heroic. Ōnoki later asks Boruto why didn't tell Sekki the truth about him, and Boruto says it'd be no use. Ōnoki tells Sekki Boruto will help him find his Heart Stone, telling Boruto under his breath that if he finds it, they'll be able to leave with Sekki. Sekiei thanks Mitsuki for coming while the two watch over Kirara and Kakō. The doctor reports to Kū that the juinjutsu on Mitsuki's heart is making analysis difficult, and that to make use of the technology behind it, they'd need human hearts for each of the synthetic humans. Kū ponders what to do, as Ōnoki wouldn't approve sacrificing humans for them. Akatsuchi leaves Iwagakure to inform Naruto about what happened, but struggles against pursuing Akuta. Konohamaru saves him. Boruto helps Sekki look for his Heart Stone. The two end up discussing, and Sekki attacks Boruto with his technique that doesn't require chakra. Boruto dodges it easily, but later notices the damage it caused to the rock Sekki hit. When Ōnoki's back gives out, Sekki gives him a back rub, like he used to do for his grandmother. Something in the plains watches the three. Konohamaru determines the area most heavily guarded by the Akuta. The doctor prepares Shikadai for a procedure, but he escapes using his shadow to stop himself from inhaling knockout gas. Sekiei informs Kū that Kirara's genjutsu is failing. Konohamaru infiltrates Iwagakure. When Sekki's resolve begins to falter, Ōnoki passes on words the First Tsuchikage said to him. Boruto and Sekki go get more water, and are attacked by a giant wolf. Boruto has Sekki use his technique, and propels him so he can land the hit on the wolf. The stone he was holding during the attack turns out to be his Heart Stone, its side looking like Sekki's grandmother. His stone glows, along with others in the ground, pointing the way out of the plains. Sekiei reports to Kū that Kontsuchi is regaining consciousness, and Kū decides to take control of Iwagakure. Ōnoki stands by his plan to Boruto, and says he has more to show him. Kū looks at his hand, which is beginning to crack down.
|Boruto Uzumaki||Yuko Sanpei||三瓶 由布子||Sanpei Yūko|
|Shikadai Nara||Kensho Ono||小野 賢章||Ono Kenshō|
|Konohamaru Sarutobi||Hidenori Takahashi||高橋 英則||Takahashi Hidenori|
|Ōnoki||Tomomichi Nishimura||西村 知道||Nishimura Tomomichi|
|Mitsuki||Ryuichi Kijima||木島 隆一||Kijima Ryūichi|
|Kū||Subaru Kimura||木村 昴||Kimura Subaru|
|Sekiei||Takehiro Urao||浦尾 岳大||Urao Takehiro|
|Doctor||Tomohisa Aso||麻生 智久||Asō Tomohisa|
|Akatsuchi||Kenta Miyake||三宅 健太||Miyake Kenta|
|Sekki||Keisuke Machiya||町屋 圭祐||Machiya Keisuke|
|First Tsuchikage Ishikawa||Takashi Kondo||近藤 隆||Kondō Takashi|
|Ōnoki (boyhood)||Taira Kikumoto||菊本 平||Kikumoto Taira|