First of all, you have something strange going on in this sentence: "Words in the magazine such as “shoujo kai”, “shugo chara”, names of authors, anime and manga series suggest that the audience must have prior knowledge about these names and terms in order to comprehend them." I can't sort this out as to meaning, so you possibly [hedging word] have a fragment with a run-on clause or two run-on fragments. I can't quite [hedging word] tell. Is this below what you mean to say?:
Words in the magazine such as “shoujo kai”, “shugo chara” and the names of popular anime authors plus allusions to anime and manga comic book series suggest that the audience must have prior knowledge about these topics and terms in order to comprehend articles including them.
On another topic [transition phrase], while it is accepted wisdom that writing in passive voice is to be avoided, that is only true if your primary focus is the actor in the thought instead of the acted upon thing. In other words, if your greatest focus in a sentence is "the magazine", then, certainly, write active sentences that emphasize "the magazine" (though this will get pretty dull after you've listed three or four or more things "the magazine" does). If, on the other hand, your focus is the acted upon thing, i.e., the font, the color, the words, the form of address, then, please, do feel free to write passive sentences that make the object of the magazine's action the Subject of the sentence: "The fonts used by the magazine ...."
Passive/active usage is often misunderstood: it is forgotten that passive construction performs a specific function, and if your goals are best met through employing that function, then passive construction is a viable and successful option. Again, the function is to intentionally focus your sentence and the reader's attention on the acted upon thing, on the object of the actor's action. For instance, if you care more about the dog than the post-person and you want your reader to care more about the dog than the post-person, then you will write: "The dog was hurt by the post-person." Conversely [transition word], if you care more about the post-person, you will write: "The post-person hurt the dog." Choose active/passive according to your intention and focus (or according to your instructor's instructions ...).