Drinking completely with ~終わる


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Chino explains that for coffee fortune telling, after the coffee is completely drank (finished drinking), fortune telling is done on the remaining patterns.

チノ:
()()わった(あと)(のこ)ったコーヒーの模様(もよう)(うらな)んです」

In this sentence, ()わる is used because finishing a drink is the normal completion of the action of drinking.

Step:
「①()おわる

The first step listed in the background is finish drinking.