185k is not a lot? Today it is, maybe not compared to 5 years ago when CD was the thing to have, but today it is a lot.
compared to the period from No Way to Say all the way to HEAVEN where all of them reached 300,000+, no it is not a lot of people as her fan base is really ~300k. if a lot of people did like it, this single would have easily sold 300k+ because it had ayu in it.