Under the Same Moon (2005)

When Tetsuya (Yosuke Kubozuka) was 10-years-old he met Emi (Meisa Kuroki), who suffered from a heart disease. In hopes to cure Emi's condition, Tetsuya decided to become a doctor. Following through on his dreams, Tetsuya is now a doctor and is about to marry Emi. One day though, Tetsuya hears about Don (Edison Chen). Tetsuya remembers the times he spent with Emi and Don as a child and also feels insecure about Don.