Izumi Tonic Adersening Serum by Shu Uemura. | The Izumi tonic serum hydrates, softens, and thickens the hair fiber, visibly increasing the sensation of volume in fine and weakened hair prone to breakage. It helps strengthen the hair fiber and provides shine for a stronger, silkier, denser, and more radiant finish. Its luminous formula, based on rice water, provides strength and hydration to the hair, conditioning and caring for it. Benefits of the Izumi tonic serum: | Thickens the diameter of the hair fiber. Provides density and body to the hair. Strengthens the hair fiber to improve its resistance. Provides hydration to seal split ends. | Adds shine and provides a healthier finish.