Naruto is an excellent related text for Belonging in my opinion, as the idea of "bonds" is undoubtedly one of the major concepts addressed in this text, and throughout the series, Kishimoto addresses this concept numerous times, with the most notable examples being Naruto's struggle to belong at the beginning of the series, Gaara's struggle to belong (which can be juxtaposed with that of Naruto's), the Naruto vs. Sasuke battle in the Valley of the End (which was also the scene I used in Section III of my Area of Study exam), the concept of the "Will of Fire", and even the character Sai, to a lesser extent. Basically, the major ideas relating to Belonging in Naruto all involve some of its major characters (Naruto, Sasuke, Gaara and Sai), and one can either address one of these characters' back stories in an essay, or link two or more of them together. On top of all of these concepts, many excellent visual techniques used by Kishimoto to convey his ideas on belonging (for example, the statues at the Valley of the End, which juxtapose the two groups to which Sasuke belongs to, the Kanji on Gaara's forehead which means "Love", and a scene at the end of the Naruto vs. Gaara battle, in which a leaf falls from a tree and lands on a pile of sand on the ground, symbolizing the reconciliation of the alliance between Konoha and Suna) can also be mentioned.
The greatest thing about Naruto as a related text is that it does not only address the concept of belonging in one way or another (something even most of the
prescribed poems by Peter Skrzynecki tend to do), but addresses this concept through the back stories of numerous characters in different cases and situations, meaning that a lot can be written about this text in relation to belonging. However, not all of this needs to be addressed in an essay, since there is not enough time and space to do so anyway. Because there is so much more belonging-related material in this text than what is required to write about in an essay, as long as this text is understood, one can easily enter the Area of Study exam without the need to worry about whether or not his or her related text can be used to answer the question asked in Section III, since one can choose to write about either Naruto, Gaara, Sasuke, Sai or even link the stories of two or more (though I would not recommend more) of these characters together, depending on which case suits the question the best. And choosing a flexible text is something which I believe is
extremely important for this current Area of Study given by how specific it is, which means that it is not uncommon to walk into the Area of Study exam for Belonging only to find that one's related text cannot be used to answer the specific question asked in Section III, though the choice of a good text like Naruto can prevent this from happening (more information about my views on this current Area of Study can be found in my reply to
this thread).