Minister Of Foreign Affairs
noun
An outside tasks minister (大臣) is someone who is tasked with dealing with things that are outside the country. This is the minister of foreign affairs.
がいむだいじん
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
とにかく、手短に言うとね、フグと僕は外務大臣について口論をして、それ以来、僕は彼に会っていないんだ。
Anyway, to make a long story short, Fugu and I had an argument about the Minister of Foreign Affairs and I haven’t seen him since.