@Aretheus I once asked the same question and they told me that it's harem "since the mc keeps more than one girl"... I was speechless at that moment, I was like " that's bigamy/ polygamy! Use harem when there are more people involved ", but in the end didn't even bother anymore
I'm not up to date with the goings-on in Kirishima Fansub, but is there a reason why it isn't being translated into English when they (I'm assuming) have the raws and are translating it into Spanish?