"Homeless Japanese woman arrested after living undetected in man's closet for a year"

I read this funny piece of news online.

"she managed to go in and out of the house unnoticed, as well as details of her life inside the closet, and if she had taken anything else besides food.
She had moved a mattress into the small closet space and apparently even took showers, Itakura said, calling the woman "neat and clean."

My brains fumbled and wondered how did the woman did it.
What a stunt/feat. You call it.