Starbucks, Yongsan I'Park Mall 1F

A Starbucks on the ground floor of the Park Tower apartment arcade, five to six minutes on foot from Ichon Station Exit 1. It opens at 07:00 every day, which suits a morning meetup before a visit to the National Museum of Korea. Buying a drink gets 120 minutes' free parking in the arcade car park (Starbucks' official store page). The restroom is a shared one outside the shop, with the code printed on your receipt. A review notes it is a single floor and not especially large.

A Starbucks Reserve on the ground and 2nd floors of Yongsan Prugio Summit, across the plaza from Yongsan Station. It opens at 07:00 every day. The ground floor has a bar and high tables; the 2nd floor is a regular room with plenty of seats for groups. A blog says the 2nd floor is up a flight of stairs and the entrance door is heavy, so it suits adults or a family meeting before a KTX more than a stroller. Buying a drink gets 180 minutes' free parking in the building car park (Starbucks' official store page).

A Tous Les Jours (bakery chain) inside the Yongsan Station building. It opens at 05:30 every day, so you can pick up bread, a sandwich and coffee before the first KTX out of Yongsan. A review counts about ten tables for eating in, though it notes the space is small.

An udon and pork-cutlet chain restaurant inside Yongsan Station. It opens at 06:30 every day, which makes it the place for a hot breakfast without leaving the station. The menu has udon, udon-and-rice sets and pork-cutlet sets, and side dishes come from a self-serve bar. Reviews say it is easy to eat alone and tables turn over quickly.