His father had an affair with a German princess and what came from that union was the handsome Shinobu who resembled his mother. His parents were separated due to unequal birth and his mother was married off to someone else. His father could not stand the sight of his son who looked eerily like his lover and spent his years away from Japan until he died. As a result Shinobu spent his time with his grandparents whom he loved dearly, which explained why he was willing to marry Benio. He's a romantic at heart, and attempts to court Benio in this fashion usually comes to naught. :)

(Source: S-Cafe)