Koukyuu no Renkinjutsuhi Aku no Hana wa Ougon no Koi wo Yumemiru

Is she a villain? Or is she just...? A Chinese harem suspense story where the protagonist uses alchemy to overcome obstacles!

Byakuren, the eldest daughter of the Yanagi family, is rumored to be bullying her half-sister Mulan due to her arrogant and cold attitude, and even her maids fear her. However, this is all an act to protect her sister. Byakuren enters the harem as a candidate for queen and begins to work towards achieving a certain goal, but with the instigation of those around her, things gradually diverge from the scenario Byakuren had envisioned...

(Source: Kadokawa, translated)