Bonjour

Bonjour is one of the main cosmetics chains in Hong Kong. Sasa is the other one. This location is located on Bute Street in Mong Kok next to the footbridge that connects Grand Century Place/​Mong Kok East Station with Mong Kok Station.
The store actually has three different entrances since it takes up multiple storefronts. While Bonjour is known for their cosmetics and fragrances offerings, it has commonality with the two drugstore chains, Mannings and Watsons.
While cosmetics are the main offering, Bonjour has a nice selection of drugstore products. Particularly Chinese medicines and healing oils. And the prices seem to be the same or better at Bonjour than at the two drugstore chains based on a product comparison I did on a few items.
The store also has a nice food and snacks selection including some that are imported. There is even an area here in the right side back of the store that is full of Japanese snacks and groceries.
The only issue with this store is that the aisles are small and the checkout location seems to be oddly placed near the middle of the store.
If you are looking for a drugstore item, you should check out Bonjour to see if they have it. You might save a few bucks here rather than going to one of the drugstore chains.