Yes and no. It is BUT in terms mostly of jp shoujo standard of reverse harem: the "Everyone is crushing/pinning n falling for one girl who either chose no one or pick one in the end".
You know how Fruit basket, Ouran host club, Akatsuki Yona, Uta no Prince same etc are tagged as reverse harem but aren't actually one in terms of reverse harem in literature since mc doesn't end with everyone like in Men's of the harem, That one time I got reincarnated in an otome (inaccurate title I don't remember its something along the line they all sound the same).
So yeah if you're into that "everyone has a one sided crush on mc" reverse harem interpretation. It is one.
If you're searching that "mc loves and end with everyone" reverse harem interpretation is NI. The story is still on going. Nv haven't chose anyone yet. (tho shown signs of love to one but forgets soon so it's not that serious)
so before i dive into this, can anyone tell me....... IS THIS HAREM OR NOT???