If you're looking for manga similar to Dotei Terminator Girlfriend, you might like these titles.
In the not so far future, in present-day Japan, a secret game is played for boys who have awakened their sexual desire, its name is "LuvSlave". In "LuvSlave", the boys make a slave contract with an older girl, and play against each other in a card battle game, the master (boy) orders his slave (older girl) to use lewd outfits or techniques and if the slave agrees to do so, then such actions can be performed. In other words, it's a game that tests the love between master and slave. Right now the burning love between the boys and their partners is on an exciting increase!
Rumors tell of Zephyrus, a beautiful and intoxicating woman who lives in a small island in the South Pacific. She's known to seduce all she meets, and not everyone who visits her leaves alive. In World War II, two soldiers become captivated by Zephyrus, and in the present, send one of their sons to investigate her recent appearance. Why has Zephyrus not aged a day since twenty years ago, and what plans does she have for the world?
In a world where heroes fight against evil from space sometimes they get hurt... and in comes a man with special powers... a massage that heals.
Haruki is a teenage boy who has two friends that are not very ordinary. Ayana has been transformed to be part dog, as shown by her dog ears and tail. Ayana also has enormous lactating breasts. Airi, on the other hand, is a cyborg girl, and she's got tons of mechanical gadgets. The story begins when Ayana and Airi both want Haruki to join their club, and Haruki must pick one over the other. Ayana's science club has more to do with transforming living things, whereas Airi's has to do with more mechanical science. Their attempts to persuade Haruki to their side tend to be full of nudity and sexual arousal. Haruki is going to have a bizarre school life.
High in the sky is the floating city of Garvia - a place where even inanimate objects have spirits, and those with especially strong spirits can manifest as gods and wreak havoc on the city. Here, spirit mediums are tasked with pairing up items to human masters who they are compatible with, an important duty since making the wrong match could have dire consequences. Here, the adorable high-ranking spirit medium Miles Erankston and her partner, the over-amorous god of destruction Gikaku, must deal with the unusual quirks of their professions.
Includes the following chapters:
Two aliens are sent to Earth to scout for resources: that's how their adventures in Tokyo begins.
Follows Kyuuichi Shinogi, a male biology student who lives in an apartment near a helpful female neighbor/friend, Ayaka Takarai. One day, he is visited by aliens who demand that he raise their baby for a year... or else the world is history. The baby is apparently human, and is raised the way humans are: through breastfeeding. Kyuuichi's sex is not a problem for the aliens: they give him a simple device that switches his body to a woman's with the mere touch of a button. Conveniently, Kyuuichi's female form is very well-endowed. Although she's understandably confused and uncomfortable by the whole situation, Ayaka helps Kyuuichi out as he navigates the unfamiliar experience of raising a child - and breastfeeding it in particular.