I asked a friend of mine to accompany me to the little repair shop around the corner; I had visited on my own, suspecting that I had a leak (as the air seemed to be draining out in a manner of days), but I wasn't sure how to communicate the fact. The guy seemed to tell me in what I could only describe as a heavy, gibberish accent, that the tire was okay and just needed air.
Long-story-short, I did indeed have a flat and required a patch on the tire's inner tube. But more importantly, I learned a new word that day from my friend: パンク（した）- to get a flat tire.
Ah, yes - "punk" as in "punctured."