The supporting character's harem is very normal - Chapter 464 God’s Eyes

Hanazawa Hanako was a young otaku girl, technically a hikikomori, a degenerate, and a netizen. She died though. (LOL)So naturally she got yeeted to a fantasy world to save it from the demon king.When asked what buff she want: “Just give me the whole Internet then.”

A botched rescue mission with an unknown objective cost Zhou Yu his team members, while leading him progressively closer to the multinational biotech corporation Juli’s research core.

In order to protect his botanist younger brother Zhou Qing, Zhou Yu accepted employment under the Juli Corporation, and is dispatched to a parallel world—Nibelungen.

Nibelungen’s biological systems are completely different from the world Zhou Yu is from. To live in this place, Zhou Yu must follow three great laws:

The first law, fear is the sign of the hunted, so you must never show fear.

The second law, the more beautiful an organism is, the more dangerous they are. Do not approach them, and do not trust them.

The third law, do not be misled by the mimicry of S rank organisms. They understand your mind, and they know how to entice you. Always remember that they have no human emotions or love. All humans are no exception to them.

Finally: We wish everyone can live happily in Nibelungen.

- Description from Novelupdates

Kōdo Ikusei Senior High School, a leading prestigious school with state-of-the-art facilities where nearly 100% of students go on to university or find employment. The students there have the freedom to wear any hairstyle and bring any personal effects they desire. Kōdo Ikusei is a paradise-like school, but the truth is that only the most superior of students receive favorable treatment.

The protagonist Kiyotaka Ayanokōji is a student of D-class, which is where the school dumps its “inferior” students in order to ridicule them. For a certain reason, Kiyotaka was careless on his entrance examination, and was put in D-class. After meeting Suzune Horikita and Kikyō Kushida, two other students in his class, Kiyotaka’s situation begins to change.