Thread:Kakarots/@comment-26091443-20180406202920/@comment-26091443-20180406204247

https://netabare-mangacafe.info/「僕のヒーローアカデミア」ネタバレ-178話%E3%80%80確定/

Here. Just look for the panel where they say her full name in the translation.

I should also note, it's very easy to tell family names and given names a part in Japanese. "Manami" is clearly a given name.