Lavina

Gokudera's deceased mother. Lavina was a skilled pianist with whom Gokudera’s dad had fallen in love with, and eventually had an affair with, resulting in the birth of Gokudera. However due to Mafia laws, Gokudera was taken away from her after his birth, with Gokudera announced as the child of Gokudera’s dad, and his legal wife, Bianchi’s mother, with Lavina only allowed to see him for three days out of the year. Source: reborn.wikia.com