Sena is introduced as a 20-year-old woman who owns a Lotus Super Seven racer vehicle, she was married to Daimaru after meeting him in a highway where she usually drives around before being in love with him. Sena was soon married to Daimaru and was also the co-owner of the ZAPPER motorbike shop. She manages the place if Daimaru is not around.
Though she and Ken had their differences, mostly in age, Sena truly cares for him like he was her own son.
(Source: Wikipedia)