Well, not really. Most of Daiso that is in Jusco, is under Jusco.
But some branches for example, Daiso in One Utama is under a different company which I used to work with and the boss have quite a few branches under him.

Those Daiso with black sign like the one in IOI mall in under a different company.

As for the mask, yep, I used it already but not very effective (on me at least). But people always buy that mask. 1 time a customer bought 40pcs!
Hmmm, I never got the chance to ask my boss because he is not really a talkative guy.
But yes, the business is good. Even in the mall that deemed "not as busy", the sales are at least 3k on weekdays and on weekends 8k is not a problem. Festive season, sales can shoot up to 15k.

The OU branch one, the highest sale was 25k. The store is super tight but people still come.

I was a cashier and 1 time, a couple bought those reusable foldable bag,69 units 

My colleague told me she had a customer, bought 1k worth of make up items.