sponging off someone; living rent-free
Describes the lifestyle of a 居候 (isōrō): staying at someone else's home without contributing to rent or food costs. Often carries a negative or self-deprecating tone.
Until I found a job, I was living rent-free at a friend's place.
My freeloading lifestyle has dragged on, and I'm starting to feel really awkward about it.
居候 is the person who sponges off others; 居候生活 refers to the lifestyle or state of being a freeloader.
寄生 is a stronger, more biological or metaphorical term for parasitism, while 居候生活 is a common, everyday expression for living off someone's hospitality.
Compound of 居候 (isōrō, 'freeloader') + 生活 (seikatsu, 'life, living'). 居候 itself originally referred to a person who stays at someone's house without paying, from 居 (i, 'being, staying') + 候 (sōrō, an old humble auxiliary verb).