What do you need to buy on day one for a goshiwon room?

You are right that furnished means a bed, a desk, a chair and a wardrobe. Here is what you actually need on day one versus what can wait.

Buy immediately (day one or two, roughly 60,000 to 90,000 won at Daiso and a supermarket):

- Bedding. Some goshiwon provide a basic set, many do not. Ask before you go shopping. A duvet, cover and pillow is 30,000 to 50,000 won at Daiso or Emart.
- Towel, toiletries, toilet paper, slippers for the shared bathroom.
- A drying rack. 10,000 to 15,000 won and you will need it in your first week.
- An extension lead with multiple sockets. Goshiwon rooms have very few outlets and they are never where you need them. This is the item people buy on day three and wish they had on day one.
- Hangers. The wardrobe will have two.

Buy in week one:
- A humidifier if you arrive in autumn or winter. 20,000 to 30,000 won and it prevents the nosebleeds and dry skin that catch everyone out.
- Earplugs and a small fan for noise.
- A desk lamp if the room light is harsh, which it usually is.
- Storage boxes that fit under the bed. That is your only extra storage.

Can wait or skip entirely:
- A rice cooker or induction plate. Useful, but see how you use the shared kitchen first, and check whether your building allows appliances in rooms.
- Anything decorative. Wall space is limited and many buildings do not want things stuck to the walls.
- A mattress topper. Goshiwon mattresses are thin, but try it for a week before spending — some people do not mind.

The one thing worth spending real money on: a decent pillow. It is the thing people mention most often afterwards, it costs 20,000 won, and you use it for 300 nights.

Daiso covers almost all of this for very little. Go there on day two with a list rather than buying things piecemeal over three weeks.