Why Do Varchar And Nvarchar Return Different Resultset In A Search?

CREATE TABLE #TEST (Keyfield varchar(30) NULL)

INSERT INTO #Test (keyfield) VALUES ('M-S Logistics');

INSERT INTO #Test (keyfield) VALUES ('Monster Racing');

INSERT INTO #Test (keyfield) VALUES ('Mueller Farms');

DECLARE @Search AS nvarchar(30), @Search2 AS varchar(30)

--Query 1

SET @Search = 'Monster Racing'

SELECT TOP(1) keyfield FROM #Test WHERE keyfield >= @Search;

--Query 2

SET @Search2 = 'Monster Racing'

SELECT TOP(1) keyfield FROM #Test WHERE keyfield >= @Search2;

-- Why does query 2 return different result than query 1