The Sky is Mine Ver. 2001

(from ebookjapan):

The Yasuda Group, a conglomerate said to be capable of founding a small independent country with just one family, had a custom. The heir to the family must find a wife who is approved by all members of the family and bring her home.

The prospective heir, Ippei Yasuda, embarks on a journey that may never end in order to meet a wonderful woman.

As Ippei continues to grow and develop through repeated encounters and partings, he learns of the disappearance of his mother, who left him when he was very young. ......