Manatsu no Eden夏日的伊甸园 ; 真夏のエデン ; 真夏的伊甸园

From Sound of Jewels: Mizuka met a strange boy when she was 13. He was her first love. But when the summer ended, even if they promised to see each other again, Mizuka never saw him again. 12 years later, Mizuka meet the same boy again. She's so happy until she found out that he has a twin brother...