Best way is to not live like the typical person here does. Dont crank up the heat and close everything up. Heat + Moisture = Mold. Covering up the problem or washing the walls doesnt do much as unless you use solid bleach they will just grow back.
Make sure that whenever you cook you open the windows to let the air out as you add heat to the room. Any day when you will be out and the sun is shining crack a window.
Close the door to your bathroom when you shower and if you have any kind of ventilation in it make sure you run it after you are finished. If you have a window open it up.
The easist way to get rid of the mold is to make your apartment unfavorable for it. Keep it clean, dry and warm (not hot and sticky). I really think it has about 10% to do with the wallpaper or glue and 90% to do with the style of life. Same thing goes for flies and cockroaches. You can kill them all you want, they will be back next week if you dont make the conditions unfavorable to them. Clean and dry makes life so SO much beter.
Do you blame the smell in yor fridge on the kimchi or the quarter inch of old food crust stuck to the bottom of the thing- If you chose kimchi, you are wrong.
**A very good tip is to do any washing after you dry your place out. If you wash then dry it could grow back under the walls in a crappy apartment where it is going to be wet for a long time. Such as if they did the "just paint over it" method most dirty Ajuma landlords use. Now you have a lovely little pocket of nasty constantly feeding the rest of your place with fresh spores.
If you talk about the walls of a building, on which you are not responsible at such a long term fight, I think the most appropriate way to prevent those horrible creatures, ask that to the legal agency or agents to remove the walls. They are not yours, that you are definitely not the cause of your environment.
So no worries.
I read once that all wallpaper or paint is supposed to be removed and replaced when a new tennant moves in. I havent ever heard of someone moving into an apartment in Korea that was even properly cleaned.
What legal agency would the person contact to have their walls removed? That seems a little extreme.