This is more commonly known as the Tenchi Complex. Seeing as how it came out in 1992, and Nadesico came out in 1996, I think the former is the proper term. Other shows, such as Photon: The Idiot Adventures, Dual, and Love Hina follow in this line (Photon and Dual were, incidentally, made by AIC, who created all of the Tenchi series)

Tenchi suffers from much of the same problems as Tenkawa Akito, except Tenchi never makes up his mind about whom he likes (as opposed to Akito, who does).