Kibun wa Hard-Boiled

Tokugawa Masamune is the next in line of the Tokugawa school of swordsmanship. But for the clan's misfortune, he's ungifted in about every way imaginable, except he is somehow smart enough to make a life like a robot girl who has a leaking problem in her pants; she also lays eggs. And so it happens that those very eggs become rather important for Masamune in the near future.

Note: Originally, serialized in Shonen King magazine with the title "I Want An Egger (ア・ウォ・ナ・エッガー)". Later collected in seinen line Play Comic under the new title with added illustrations.