I don't find Sejun annoying (at least for now) but I agree the story is dragging. They spent a lot of time building up to the ribbon Kingdom conflict. Since that's been over, it just feels like all the other arcs are more like fillers. There hasn't been a clear direction
This was low key one of my favorite comfort shows but its been dragging for a while now. Sejun is also starting to annoy me ngl.