。
My friends call me Ken.
Literal
Friends [topic-は] me [object-を] Ken [quotative-と] call.
Hiragana-only ぼく for 僕 softens the feel further — often used in children's books or for young-boy speech in media. The frame XをYと呼ぶ ('call X by the name Y') uses the quotative と to mark Y as the called name.