Silvia, nicknamed "Sylvie", defends Japan from the sea using a submarine. Despite her occupation as a member of the Japanese Maritime Self-Defense Force (JMSDF), she cannot swim. She has a somewhat curious affection for tangerines, and is frequently depicted eating them. Her clover pin is grey. Her name in the English-language subtitles is alternately written "Sylvia", though the opening credits and various episodes show her name as "Silvia".
(Source: Wikipedia)