Saekki is a Korean word that means "newspaper delivery person". Have you ever seen someone riding a bicycle really early in the morning with lots of newspapers in a bag? That person is a saekki.
They wake up early and have to make sure that all the papers are delivered to the right addresses. It's a very important job because people rely on getting their newspapers to know what's happening in the world.
It can be a tough job because saekkis have to work in all kinds of weather, like rain or snow, and make sure to not get lost while delivering the newspapers. But they are very dedicated and responsible people who take their work seriously.