STEEL ANGEL KURUMI ZERO

Sometime in the distant future, Kurumi, Saki and Karinka share an apartment with another girl named Excelia. One day, after school, Kurumi tells everyone that she is in love with a man she met named Michihito Kagura, but she doesn't know when she will see him again. (Source: Anime News Network) — Description from AniList community (anilist.co).