との

との is the quoting と plus の. It turns a piece of reported content into a description of the noun after it: "the news that", "a message saying". The clause before it is in the plain form, and a noun or な-adjective may drop its だ.

The noun after との is a kind of message or view: れんらく連絡, うわさ噂, へんじ返事, はっぴょう発表, いけん意見, ほうこく報告. Compare the plain quote, where と goes straight to a verb.

との or という

という does everything との does and more. It can also name or define a thing: とうきょう東京というまち町, "a town called Tokyo". との only passes on what was said, decided or reported, and it sounds more formal – news reports, business mail.

• × 東京との町 → 東京という町

とのことだ

At the end of a sentence, とのことです passes on what you were told: "I'm told", "apparently". It is the polite way to relay a message from someone else.