Zhu Yu knew Jiang Bei; to be precise, the two had a history, and it wasn't a bad one. The reason things had become so strained was, indeed, Yuan Boshi.
Jiang Bei had previously been signed to Xingmang and had entered the entertainment industry solely because of Yuan Boshi. Once she discovered that Zhu Yu and Yuan Boshi were together, she had a massive blowout argument with them both, then immediately terminated her contract. At the time, her career was on the rise, and she even had a film pending production.
She ended up paying the breach-of-contract penalties herself, went abroad, and subsequently vanished from the public eye.
Chapter 55