Hello so im looking a manga i can remember the plot and all that but not the name and i cant seem to find it so basically we have a main female lead who falls in love with her childhood friend but her friend gets lost in the sea and everyone thinks he died but he actually lives and loses his memory then he meets someome else and has a child with her but they both die and our female lead adopts the child and the child falls in love with her they have an age gap of 16 (if i remember correctly it was kind of an old manga?)
if anyone recognizes this manga please let me know i cant find it

Suna no Shiro?

Quote from NeNee

Suna no Shiro?

Yes it is this one! Thank you very much!!!