Hinge
In the tree district of town you can buy a lot of tree products, including doors. With those doors, though, you always need hinges.
すう
からくり
None
After you buy it, you need to lubricate your hinge with soup (すう). You've found that soup works better than anything else on the market for keeping your hinges squeak-free and moving smoothly.
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.