From Renta:

Professor Ethan Shoyo Smith is a renowned botanical researcher. When his assistant goes on leave, his mentor introduces him to Takumi, a handsome research student. Despite Ethan's exotic looks and flashy reputation, he leads a less than glamorous life. He begins to worry that although Takumi works every day without complaint, he's somehow disappointed to be working with him.

One day, Hanako, a plant that Ethan is researching, attacks Takumi, causing him to inhale her nectar and be overcome with lecherous desire. Ethan tries to help calm him down, but is brushed off when Takumi says he'll take matters into his own hands. Before Ethan knows it, the tables have been turned...! The up-and-down love story of a clueless scientist and his cute assistant!!

Official English Release