Rito Yuuki never gets a break—he's always finding himself in lewd accidents with girls around him. Although his heart still yearns for Haruna, his childhood love, Rito can't help but question his feelings for Lala, the alien princess who appeared in front of him and declared she would marry him. But now, it's not just Lala he has to deal with: her younger twin sisters, Momo and Nana, have also travelled to Earth, wanting to meet their older sister’s fiancé, and just as luck would have it, they end up staying at Rito's home. Meanwhile, amidst the bustle of his new family members, Yami, the human weapon girl, begins her pursuit for Rito. It's not an easy life for Rito as he deals with uncertain love, punishment for being a pervert, and a girl dead set on murdering him. [Written by MAL Rewrite]

As close encounters of the twisted kind between the residents of the planet Develuke (represented primarily by the female members of the royal family) and the inhabitants of Earth (represented mainly by one very exhausted Rito Yuki) continue to escalate, the situation spirals even further out of control. When junior princesses Nana and Momo transferred into Earth School where big sister LaLa can (theoretically) keep an eye on them, things SHOULD be smooth sailing. But when Momo decides she'd like to "supplement" Rito's relationship with LaLa with a little "sisterly love," you know LaLa's not going to waste any time splitting harems. Unfortunately, it's just about that point that Yami, the Golden Darkness, enters the scene with all the subtleness of a supernova, along with an army of possessed high school students! All of which is certain to make Rito's life suck more than a black hole at the family picnic. Unless, of course, a certain semi-demonic princess can apply a little of her Develukean Whoop Ass to exactly that portion of certain other heavenly bodies! (Source: Sentai Filmworks)

The dispassionate, transforming assassin Golden Darkness returns to peer deeper into the mysteries surrounding her new life, while a sinister Nemesis manipulates her younger sister Mea from the shadows. Along with their newly discovered mother, Tearju, this previously estranged family quickly becomes the center of everyone's attention. On the other hand, Princess Momo's Harem Plan stands on shaky ground amidst Rito's inability to confess to his longtime crush Haruna, who has grown feelings of her own. But things aren't as peaceful as they seem; an evil force looms amidst the innocuous commotion, threatening to eclipse the love, happiness, and friendship of Rito and his harem. Only the light of love can hope to banish the shadow. [Written by MAL Rewrite]

Since 1973, an invasion of aliens upon Earth known as BETA has driven human civilization to destruction. In order to defend themselves from this enormous mass of enemy force, mankind has developed large humanoid arms called Tactical Surface Fighters and deployed them to its defense lines through out the world. However, its efforts could only slow down the impending defeat, and mankind has been forced to abandon the major areas of the Eurasian Continent. For 30 years, they have been caught in an endless war against BETA without any hopes of victory.

Now in 2001, Imperial Japan faces difficulties in the development of the next-generation of Tactical Surface Fighters (TSF) as it defends the front lines of the Far East. The UN has proposed a joint development program between Imperial Japan and the United States as a part of its TSF international mutual development unit, the Prominence Project.

Yui Takamura (a surface pilot of the Imperial Royal Guards of Japan) is given the responsibility of the project and sets off to Alaska. Meanwhile, Yuya Bridges, also a surface pilot of the US Army, heads to the same destination.

They never had any idea just how drastically their encounter would change their fates.

This story of internal dilemma takes place during the development of the new Tactical Surface Fighters, the most crucial and effective weapons against BETA. And this time, the stakes are much higher than a handful of lives and our sanity.

All we can do is fight.

(Source: Muv-Luv Total Eclipse Official English Website, edited)