Petit Roid 3

"The fate of the world hangs between his legs!"

Shibamata Youichi was just another ordinary student, that is until one day his grandfather gave him 3 little android girls to serve him. They can do anything you wish for but there's a catch... you gotta constantly reward them with sex or else they're gonna go BOOM! Oh, and they have a combination feature like all good super robots do!

Petit Roid 3 is a Hentai Manga series made by Tomohiro Kouda. Its premise and humor makes it a whole lot Better Than It Sounds compared to most H-manga out there.

Tropes used in Petit Roid 3 include:

Actually a Doombot: Robo-Haru-nee, an android clone of Youichi's childhood friend/crush.
Arm Cannon: Natsuko
Beach Episode: The finale of the series.
Blonde, Brunette, Redhead: Kirara, Mitsuki and Karin respectively.
Bokukko: Karin, the token tomboy of the three Shibamata androids.
Catch Phrase: "I'll self-destruct!" Often used to threaten Youichi into sex.
Classic Cheat Code: Entering the Konami Code on the girls' nipples supercharges their sexual sensitivity.
Combining Mecha: All of the robot girls can combine into teen-form (two girls combined) or adult-form (three). However, it's not quite clear how this works since it's always done off-panel. Even Youichi, who sees the whole thing happen right in front of him, isn't quite sure himself: -->Youichi: I keep seeing it, but I still don't get how they fit together.
- There's also the Grand-form where all twelve girls to turn into a Humongous Mecha.
Cut Short: Intentionally done to show that life goes on and nothing will ever change Youichi's predicament, much to his chagrin.
Does Not Like Men / Hates Being Touched: Kimizuka's own android, Natsuko. That is, until she met Youichi.
Dragged by the Collar: Haruka does not want to leave Youichi... Robo-Haru-nee makes her.
Earthshattering Kaboom: What can possibly happen if all of the girls self-destruct at once.
Elegant Gothic Lolita: Kirara
Exactly What It Says on the Tin: The title of the series. Shibamata's androids are all petite... and there's three of them.
- Artifact Title: Becomes this when more androids are introduced, especially Raika. See the Sixth Ranger entry below.
Girlish Pigtails/Princess Curls: Kirara
Hair Decorations: It's also one way to tell which girl is an android.
Helicopter Hair: Another of Kirara's abilities with her hair.
Here We Go Again: In the end, just when Youichi thought that he had everything figured out and can finally relax, his grandfather sends him eight more androids... all with the same Rabbit System as the original three.
Hidden Agenda Villain: While Mimiko does have a grudge against Shibamata's androids, she still loves and cares for Youichi that she feels like she's betraying him.
Hime Cut: Minagawa Haruka
Juggle Fu: Raika does this... with Youichi in a bag, while she transforms.
Laser-Guided Amnesia: Done to Mimiko after a not-so intimate session with Youichi. Still doesn't stop her from falling in love with him.
Lethal Chef
- Not that Mitsuki is a bad cook, but she often concocts "energy-boosting" recipes with strange ingredients she bought off the Internet.
- Played a little bit straighter with Mimiko as she is still trying to gauge her boyfriend's tastes.
Lolicon
Losing Your Head: Robo-Haru-nee after getting smacked around by Haruka. She can still perfectly function, however.
Mad Scientist: Youichi's grandfather, as well as his Unknown Rival-cum-girlfriend, Kimizuka Mimiko.
Meganekko: Mitsuki
My Sister Is Off-Limits: When Natsuko finds out that Youichi is dating her creator/"older sister" Mimiko and goes through Knight Templar-levels of over-protectiveness.
Ninja: Raika, a ninja-android.
Porn with Plot
Prehensile Hair: One of Kirara's specialties.
Rape As Comedy: When Youichi goes berserk and kidnaps Mimiko out of sexual instinct, she takes it as a chance to gauge his sexual prowess... Suffice to say, she wasn't disappointed.
Restraining Bolt: At first, Youichi was not able to have sex with his androids individually (ie - not combined), thinking it was some kind of moral restriction and to prevent him from being a Lolicon. Turns out, his grandfather just didn't have the time to implement the feature and immediately gave the girls a literal Fan Service Pack.
Ridiculously-Human Robots
Robosexual: The main premise of the story. Even after getting himself a girlfriend, it doesn't stop Youichi from getting it on with his three robot girls.
Robot Girl: See above
Self-Destruct Mechanism: The aformentioned Rabbit System that all Shibamata androids have built-in. If they don't have sex with their master/s, their loneliness will cause them to explode with the force of a small atomic bomb.
Shout-Out: Kirara uses the Konami Code on Mitsuki to activate her hypersensitivity.
Sixth Ranger: Err... she's actually the fourth... Raika joins Youichi's harem a bit later in the series.
This Is a Drill: One of Kirara's abilities is to turn her hair, along with the rest of her head, into a giant drill. She gets disoriented for a while when she uses it.
Twin Threesome Fantasy: Invoked with Haruka and her clone, but we don't see it happen until the aftermath.
Unlucky Childhood Friend: Minagawa Haruka
Yamato Nadeshiko: Minagawa Haruka
Zettai Ryouiki: Natsuko; Raika's younger form