After wandering around for a while, I went straight to CGV as advised.
As you go in, you will see an IMAX theater. If you keep going in,
(Actually, I was lost here for a while. Thank you for telling me to go to IMAX.)
Although the space inside the store is small, it is well-decorated and enjoyable to look at.
ILLIT signed poster and cheering message
[ILLIT Photoism Photography]
Messages of support from ILLIT fans
MINJU's photo on the entrance ticket...!
The last ILLIT advertisement I saw on my way out