To hear gossip or unofficial news.
うわさや非公式なニュースを聞く。 (uwasa ya hikōshiki na nyūsu o kiku)
"I heard on the grapevine that she’s leaving the company."
"私はグレープバインで聞いた彼女が会社を辞めると。" (watashi wa **gureepubain de kiita** kanojo ga kaisha o yameru to)
To be very close friends who share secrets.
to suddenly fail or collapse
to suddenly start talking about something unrelated
to be responsible for something and able to explain it
To see something from a different perspective
the secret is revealed