LISA met up with a star possibly even bigger than herself ... the viral monkey Punch!

The BLACKPINK star stopped by Ichikawa City Zoo in the Chiba prefecture just outside Tokyo, Japan to visit the monkey who went viral because other apes in his enclosure were bullying him.

The star wanted to support the monkey's habit of carrying around a stuffed orangutan by bringing her own to the zoo ... holding it up for the little macaque to see.

She also shared a few snaps of Punch hanging around his cage ... relaxing on his own in the enclosure -- with his stuffed pal close at his side.

There's no monkey business here ... just a lot of love between two of the world's biggest stars!