'John Wick 4' Star Rina Sawayama Praises Keanu Reeves and Alexandra Grant's 'Really Natural' Chemistry

Rina Sawayama has her own opinion about the Internet's Boyfriend — Keanu Reeves!

While walking the red carpet at the New York City premiere of John Wick: Chapter 4 on Wednesday evening, the actress and singer, 32, told PEOPLE exclusively that her costar and "captain of the ship" killed everyone with kindness while filming the movie.

"Keanu cares about everyone on set, even the person that's passing him water," the "Send My Love to John" singer said.

All of which was something that the Japanese-British pop musician appreciated while making her film debut in the latest Wick installment.

Another thing Sawayama admires is the relationship Reeves has with his longtime girlfriend, artist Alexandra Grant.

"They're wonderful," she said. "We actually were able to spend some time in Berlin ... had some dinners, and it was great group dinners and that was wonderful. Beautiful, beautiful as a couple, beautiful people."

The star added that the couple are "just sweet" and "really warm."

"They're just very normal, honestly," she said, referring to a group visit they took, while filming, to an exhibition of Grant's work. "It just felt really natural and just human. I don't know again, like I've used the word 'celebrity' because often I feel like Keanu can switch off his celebrity and I've really felt that way when he was with Alexandra. It just, it was beautiful. It was honestly, it was like, a whole thing."

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And it's a love that extends over decades, and generations, Sawayama noted about Reeves' viral mutual appreciation society.

"Like even from my mom's generation since Speed," she said. "He is like the Internet. He's like the boyfriend of everyone."

The new film follows John Wick's journey toward defeating organized crime organization The High Table and new villain Marquis de Gramont (Bill Skarsgard), whom Wick must battle in order to take his final revenge against the organization.

John Wick: Chapter 4 blasts into theaters March 24.