Never pour your own drink
In the West, it’s common for the host to pour drinks. They’ll start off by filling the glasses of their guests before finally filling their own. After the initial filling, if you want a refill, you do it by yourself. That’s considered courteous, but many of us Westerners toss that rule out the window.
However, in Japan, it’s custom that someone fills the cups of everyone at the table and wait for someone to fill theirs up. There’s really no special reason why this is done, but it’s a tradition that we wouldn’t want to challenge. After everyone’s cups are filled, someone says “kanpai” before everyone goes for their drink. It basically means cheers.