This is the 6969th most frequent Japanese word.
マツモトキヨシ
Matsumoto Kiyoshi is a popular Japanese pharmacy and drugstore chain.
This sentence uses 'マツモトキヨシ' as the name of a place—a well-known drugstore chain in Japan.
マツモトキヨシで化粧品を買いました。
I bought cosmetics at Matsumotokiyoshi.
Here, 'マツモトキヨシ' refers to the brand name or the entity itself of the drugstore chain.
マツモトキヨシの看板は黄色と青の配色です。
The Matsumotokiyoshi signboard has a yellow and blue color scheme.
In this sentence, 'マツモトキヨシ' indicates the specific store from which the person was asked to make the purchase.