What is the meaning of へ or への in this case:
中国では日本のアニメや漫画への人気が高いことに加え、「君の名は。」は、ネット上などで早くから話題を 集めていて、映画館によっては、予約販売ですでにほとんどの席が埋まるところも出ています。
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Sign up to join this communityへ in this case is expressing direction, similar to 海へ行く, though in this passage the direction is not physical, it is expressing the 'direction' of popularity (人気).
の is being used to make the part before it "...漫画" modify the part after it "人気。。。"
So "漫画への人気" could be loosely translated as "Popularity of Manga".
Here is an article I wrote about this topic with more examples.
UPDATE: Below is my rough translation of the passage in question for reference:
In China, building on the already high popularity of Japanese Anime and Manga, "Your Name" has quickly become a hot topic in places such as the Internet, and there are some movie theaters where tickets are already sold out and most seats are filled.