Install
You use your fingers to take down the old flag and install a new one. Flags get old, just like computers and furniture and people. So when one gets too old, you have to get on up there and install a new one in its place.
きょ
す
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You've decided to install a suit (す) where the old flag used to be. I mean, a suit is probably more durable than a flag, am I right? This way you won't have to install flags as often.
An update is needed before you can continue but you have more than one WaniKani tab open.
Finish up what ever you are doing on the other tab(s), then close them to continue.
The update will complete automatically once the other tab(s) are closed.