With You ～みつめていたい～

A long time ago, a man and a woman made a promise, stating that although they were destined to be lonely souls, they should always remain together. But by a cruel joke of fate, they were separated and sealed into two jewels that were hidden for generations. Manami, who left the country 6 years before, has found one of the jewels while traveling. He will return to Japan to meet with their friends from childhood. This will entail a meeting of the two jewels again, for the second jewel seems to be owned by his father.

[Taken from Mobygames]