I'm pretty sure this is the equivalent in English and it is usually used for long-sleeved garments, so it would work for a coat (Google provides plenty of images ;) )

Hola!
Aquí verás cómo es una manga japonesa: https://ar.pinterest.com/pin/424182858655548468/

Su equivalente en inglés, cap sleeve (a sleeve extending only a short distance from the shoulder and tapering to nothing under the arm.), podrás verlo aquí: https://www.google.com/search?q="cap sleeve"&client=firefox-...

https://en.wikipedia.org/wiki/Dolman
"A dolman sleeve is a sleeve set into a very low armscye; in fact, the armscye may extend to the waistline, in which case there will be no underarm seam in the blouse. Dolman sleeves were very popular in ladies clothing during the US Civil War."

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Note added at 29 mins (2020-01-10 11:06:56 GMT)
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See photos at: https://tinyurl.com/tdjzgno. They match photos of the "manga japonesa".

I think this is what they refer to. Check links.
The term pagoda sleeve is normally used to describe any funnel shaped sleeve.
I'm not very sure of the difference between "manga japonesa" and "manga campana" though.