If you are actually writing an essay rather than simply writing a report on the magazine, you need a thesis statement. You need a "bright idea" about the magazine that you can prove; or you can make it about something you disprove. In essay writing of all kinds, the objective is to become part of an academic "conversation" where you present a controversial, unusual, new, or otherwise debatable "argument" (meaning topic of discussion; very different from quarrel) that adds a new point of view, enlightenment, insight or interest into the topic at hand. So, in a word, as they say, unless this is simply a report, you must form a debatable idea about the magazine, present your reasons for your idea (these are called your arguments) and make a detailed and convincing case for your perspective.
Additionally, you need to look up the definitions of some words and avoid using a thesaurus until your mastery of English lexical defintions is keen enough to understand the sometimes subtle differences between similar words. Specifically, "suggests" is too conditional a word to apply to careful, painstaking, costly, deliberate marketing decisions to expand a product to an international market. Similarly, no marketing decisions are ever undertaken to "hint" at the market niche of a product: the risk of missing the meaning of a "hint"--a covert and hardly noticeable suggestion--is too great to risk the success of a marketing campaign and an entire product on. I would recommend (much more firm and confident than "suggest") that you actually mean the simple and straightforward words "prove" and "show." [Note the comma after "cultures" separating two full independent clauses. You might also add the hedging word "intended": "the magazine is intendedfor both cultures, ...." Remember that hedging and mitigating is necessary in essays.]
Both Japanese and English translations exist proving that the magazine is for both cultures, and the masthead “Shoujo Kai” shows that the genre of the magazine is anime.
Hedge: the act or a method of reducing the risk of loss of an argument; a cautious or evasive statement (Collins Dictionary): e.g., intended, perhaps, possibly, etc.
Mitigate: to make or become less severe or harsh; moderate (Collins Dictionary): e.g., may, might, could, etc.