@Kiriha It turns out that you're right, but not for the reason that you'd expect. In the raws, "Matomo" is written using Katakana. Given the fact that she already knew the MC's (Ikuta) name, I made the assumption that he was making a pun from her name and the word "Matomo." One translation being the one currently uploaded, and the other being the one that you have suggested. However, looking at the raws a couple chapters ahead, her name is indeed different (it won't be revealed for now). In other words, the use of "Matomo" is not a pun, and therefore not her name. But this still leaves the issue of why the author decided to use Katakana when writing "Matomo" instead of Hiragana. My best guess is that the katakana is used for extra emphasis like in the phrases “イイね” or "ココに注目" but I'll be asking my Japanese friends for their opinions as well.
PS: Starting off your feedback with an accusation isn't exactly the best use of constructive criticism