I'm living with my boyfriend in a 75 m² apartment with 6 rooms in all.
Your room is about 15 m² and it can be self-contained. There is a sofa bed for two people with a mattress topper, which makes lying comfortable, a 90x200 mattress (a 90x200 air bed can be added) and a TV in it. We have a large kitchen with dining table and chairs. The bathroom has both a shower and a bathtub.