Lorient no Aoi Sora

Claudine, Helena, Louis and Roger were created together in Lorient, a hamlet north of France, but their friendship in broken after they grow up and their lives follow different paths. But destiny, love and tragedy will unite them again years later... And they will find out the true value of friendship, which can be a clenched, hurtful fist, or an open, saving hand.

(Source: Arechi manga, translated)