That 旦 (a cup sitting on a saucer) is the classic 'holding a drink' prop in Japanese kaomoji — as in ( ^^)_旦~~, a face sliding a cup across the table toward you.

乾杯 (kanpai) literally means 'dry the cup.' Drinking kaomoji love to show two 旦 cups clinking — (^-^)_旦""旦_(^-^) — for a proper toast.

A face like (๑´ㅂ`๑) with a wobbly mouth and round flushed cheeks is the happy-tipsy glow that shows up a couple of drinks in.

The _ or o just before the cup — ( ^^)_旦 — is an arm reaching out to hand you the drink. It's the kaomoji way of saying 'here, have one!'

Arms-up faces like \(^o^)/ surrounded by drinks capture the loud, warm izakaya mood — the whole table cheering at once.