Seijo no Ane Desu ga, Imouto no Tame no Tokushu Maseki ya Tokushu Yakusou no Saishu wo Yametara, Ringoku no Majutsushi-sama no Moto de Shiawase ni Narimashita!

聖女の姉ですが、妹のための特殊魔石や特殊薬草の採取をやめたら、隣国の魔術師様の元で幸せになりました！

by Akira Eba, Kanon, Sajima

The main character, a young girl named Sherry, is an excellent "gatherer" who collects special herbs and magic stones. She became a gatherer to help her only relative, her younger sister Irene, a saint, but when Irene comes of age and is engaged, she abandons her and tells her to disappear somewhere. Sherry decides to leave her country and heads for the neighboring Rogue Kingdom, where magic is thriving. Along the way, she meets Aslan, a handsome magician from the Rogue Kingdom... This is the Cinderella story of a gathering nerd who turns her life around. (Source: Natalie, translated)