Got Plagiarized

[Firebolt391d]

Wait, this is a musical theme of a character from a Japanese movie series. The melody will always be exactly the same, across all variations. If the key that the arrangement took was in the original key, and as long as both of you arranged the song correctly, it should sound exactly the same as yours.

You are both plagiarizing off of the same source; the arranger from that video could just as easily accuse you of plagiarizing them. Here is another version of the same song, in the same key, with the same notes as "yours:"
https://www.youtube.com/watch?v=b1gMLSDAAlI