What is Left Behind (遺されたもの, Nokosareta Mono) is chapter 405 of the original Naruto manga.
Fukasaku explains that Jiraiya gave him a coded message about Pain before dying and shows it to those present. Naruto instead focuses on Tsunade, blaming her for letting Jiraiya go on such a dangerous mission by himself. Tsunade makes no effort to refute his claim so he storms out despite Sakura's protests. Naruto continues the rest of the day wandering town and mourning Jiraiya. He runs into Iruka, who reveals that Naruto is finally gaining acknowledgment on a village-wide scale, and offers to take him to Ramen Ichiraku, but Naruto declines. In the evening, Naruto, holding a popsicle, goes to a park and starts crying, regretting how Jiraiya was not able to see him as Hokage. Iruka tracks him down and comforts him about Jiraiya's death, saying how proud Jiraiya had always been of Naruto and how, as Jiraiya's student, he lives on in Naruto. Meanwhile, Tsunade tasks Shikamaru with deciphering Jiraiya's message alone. Although Shikamaru objects to doing the task himself, Sakura insists he does. It is revealed that shortly afterwards, Tsunade takes some time alone to cry for Jiraiya, remembering when the two met and regretting not having reciprocated Jiraiya's feelings earlier.
In this chapter the name of the store Naruto bought the popsicles at is listed as a side note. It's named the "24-Hour Convenience Store".