Manatsu no Kousen (真夏の光線; A Ray of Light in Midsummer) is the fifth single by the J-pop idol group Morning Musume, released on May 12, 1999 as an 8 cm CD. It sold a total of 235,010 copies, and reached number three on the Oricon Charts. In 2004, It was re-released as part of the Morning Musume Early Single Box and again in 2005, as a 12 cm CD. The lead vocalist of this single was Abe Natsumi. "Manatsu no Kousen" ranked as the #93 single for 1999.