@Peterquill47 A harem is usually considered a harem when many men or women all hold the mc in a special place in there hearts. It doesn't matter if there is a clear winner among them (even on chapter one). In this case, the guild receptionist makes this a harem due to her over zealous behavoir in getting the mc to trust her (she was willing to put herself into slavery just so he would trust her),as well as the fact that she thinks she owes a lot her career to him, and the fact that she would be willing to risk that career for him.
It doesn't end there however, she's also had plans to make him apart of the guild, WITH HER, should he ever give up on being an adventurer. She wants to help him out no matter cost to he own well being or livelihood, and she won't be only woman to do this either from what I've heard.
A harem doesn't require the mc to be in a relationship with any of the men/women. It doesn't even require the mc to end up with anyone when the story ends. It only requires many people of the opposite sex of the mc to want to constantly worry, and/or act on his/her behalf.
A good example of this is sword art online. It's established early on that he only cares about one women, yet many women fall for him regardless, that's why it's considered a harem, it's also why this is a harem too. At least to many anyway.
Regardless if you consider this a harem or not, this a great manga, definitely give it a try.