[a] manga is a highly polysemous word in Portuguese: some of its meanings are shared between EP and BP (including shirt sleeve and mango, the fruit), while others are different (for example, it’s used in Brazil to name a fenced pasture ground for horses and oxen.
There’s an extra meaning in EP that’s not shared in BP by virtue of the latter’s insistence in having stressed final vowel openings in some new words (the same process that gives us metro/metrô).
So, manga (usually without the article, but still a feminine noun if definiteness is necessary) is also used in EP for manga, Japanese comics. In BP, it became [o] mangá, with an open, stressed A at the end (and a change in gender as well).
If anything, it can be argued (here as in bebé/bebê) that BP sometimes fares better at mimicking the sound of the word as taken from its original language, while EP prefers to pick up things on its own and adapt them in reference to existing words. However, the opposite seems to happen when picking up neologisms that are harder to change into Portuguese – EP tends to accept some neologisms without changing them, while BP can twist them into words more closely aligned with local pronunciation.