"Naruto" has been described by several critics as a coming-of-age story. Psychologist Lawrence C. Rubin suggests that the storylines would appeal to readers of any age who have lost loved ones, or are having difficulty finding friends, or who are in other situations shown in the series. In Yukari Fujimoto's view, as the characters mature, they show respect to the adults who have raised and taught them, making it a conservative storyline in comparison to other manga of the same time period such as "One Piece" and "Air Gear". Rik Spanjers sees the difference between Sasuke (a loner) and Naruto (an optimist) as tragic, arguing that the contrast between the two protagonists' approach to the world is fundamental to the plot: "Naruto's strength grows as he gains more loved ones to protect, while Sasuke remains alone and is increasingly absorbed by his quest for revenge". Omote Tomoyuki points out that there are many comic moments in the story despite the difficulties Naruto finds himself in, but the comic elements diminish dramatically over time as Naruto grows into a teenager, particularly once Part II begins. "Shōnen Jump" began to carry comedies such as "Gintama" and "Reborn!" from 2003 onwards, and in Tomoyuki's view this is part of the reason for the change in emphasis: "Naruto" "was not supposed to provide laughter anymore".