Futaba-kun Change! is an eight-volume manga series by Hiroshi Aro about Futaba Shimeru, a seemingly normal junior high school student who suddenly discovers that he is anything but normal.To be more specific, Futaba is one day handed a girlie magazine by a fellow member of the wrestling club. Having snuck into the boys' room to read it, Futaba suddenly clicks on not just how girls are different from boys, but why it matters. And as he thinks of his good female buddy Misaki, his excitement increases — and suddenly Futaba finds himself possessed of female anatomy!Some scary moments (and the discovery that the effect isn't permanent) later, Futaba gets home, only to find out that everyone in his family changes gender upon becoming aroused, and that the person he's always thought of as a father in fact was the one who gave birth to him!Hilarity Ensues, as Futaba tries to start a romantic relationship with Misaki, deals with female anatomy issues, starts a new career as an "idol" and learns more about his/her family's heritage.Sadly out of print in the United States as of September 2010.
Futaba-kun Change! provides examples of the following trope:
During the Tournament Arc, Blanka, Zangief, Guile, and Dhalsim from Street Fighter are each seen once, with Ryu and Chun-Li making multiple appearances (especially Chun-Li). An early visit to Misaki's room reveals a collection of 9 plushies, featuring the 8 World Warriors and Sagat. (Every time we return to her room, different plushies are on display.)
Usagi from Sailor Moon can also be spotted front and center in one panel.
Gainax Ending: A rare manga version, due to the series being abruptly canceled. Turns out Futaba's family are aliens that moved away from the aformentioned Floating Island; Futaba, Misaki, and Kurin end up away from the planet for 8 years; Misaki gets gene treatment to fix her partial Gender Bender alien DNA (and thus makes herself a compatible mate to Futaba); Futaba Takes a Third Option and apparently decides to marry both Misaki and Kurin; and the entire world now knows about the aliens due to Negiri's PR efforts. There's a reason most readers just pretend the last volume never happened.
Genre Shift: Starts as a High School gender-bending comedy and ends with the revelation that the Shimerus are aliens, their homeland is a spaceship and their homeworld is a Ringworld made of ivy that has under gone a Category 4 extinction.
The Ghost: Mrs. Shimeru, Futaba's father. Her face is never seen, and only about two strips show even a part of her body.
Jumping the Gender Barrier: During their trip to the Shimeru clan homeworld, Misaki gets gene therapy to make her into a full Human Alien like Futaba and Kurin, making her suddenly an available love interest. Futaba decides not to decide.
Man, I Feel Like a Woman : But of course. Best not to think about the implications for Futana's changes. Also, Misaki during her brief period of changing into a boy.
Marry Them All: The canon solution to the love triangle, shown in the last few chapters. Futaba marries both Kurin and Misaki (who gets gene therapy on the ship to turn her into a permanent gender bendingHuman Alien like the other two).
Selective Obliviousness: Somehow Futaba has managed to make it to junior high school without noticing his family's tendency to change genders on a regular basis. Especially remarkable given the Shapeshifter Mode Lock problem.
Shapeshifter Mode Lock: Futaba is stuck in girl form while menstruating. Presumably this also happens during pregnancy.
Skinship Grope: Futana, naturally, though she tends to take it a bit further than most characters.
Soft Glass: Futaba goes through glass windows several times, including once nearly-naked, without so much as a scratch. The Justicemaker, on the other hand, can get plenty of shards in his huge head along with comical spurts of blood.
Sweet Tooth: Misaki's got a huge one; so much so that it ties in with Lethal Chef — anything she cooks for herself is unbearably sweet. And it gets better — she's so overly sugared that the swim team can't really swim — because her swimming in the pool has turned the water into a sugary equivalent of the Dead Sea, which is rather hard to sink in. At one point she makes chocolate so overly sweet, it spontanously combusts, turning it into the world's first Chocolate hand grenade!
Tempting Fate: Futaba says he has a good feeling about the school field trip; next panel the plane carrying them has ditched in the ocean.
Unknown Rival: Ms. Hiroin to female Futaba; see link in Breaking the Fourth Wall example.
Victorious Childhood Friend: Misaki, with the complication that she's going to have to share Futaba with Kurin. She earned it, though, what with going through Gene therapy to turn herself into a full Human Alien so she would be compatible.
Walking the Earth: Futana's fiancé(e) departs to do this after meeting her for the first time.