Since your school days, you've been fascinated with the Japanese language and culture. You've even been to Japan to see it all for yourself! But even then, you've realized that the only way to truly experience being Japanese is to, well, actually become Japanese. So when you saw the ad for the TG Soda, you knew that this was a once-in-a-lifetime opportunity.
You insert a quarter into the vending machine and press the button marked "Green Tea". A can falls to the bottom of the cabinet, illuminated by a mix of pink and blue light. You get it out and examine the can, rubbing your chin thoughtfully. Might as well see all the changes in action, right? Chuckling to yourself, you take off your clothes, leaving you standing naked in front of the mirror opposite the machine, before opening the can and starting to drink.
To your surprise, almost instantly you start to feel oddly relaxed. It's like your mind has been transported into the middle of a beautiful sakura garden, the breeze gently brushing past you. As you set the can down, you begin to notice changes to your body.
Your skin turns as white as snow, a little lighter than your usual Caucasian skin, while your long hair turns jet black and your irises change to a rich black. "なんだ…？" you mutter under your breath, before covering your mouth in shock. Holy shit, did you just speak Japanese?! Seems this soda's working faster than you anticipated. Talking of which, the changes now move onto the main event, the rest of your body.
Your shapely D-cup breasts begin to slowly shrink down into your chest, gradually pulling back before stopping just before they're totally flat, upon which they broaden and harden into toned pectoral muscles. Likewise, your nipples get smaller and flatter, losing their former sensitivity. You moan in a now obvious Japanese accent as this happens, clearly enjoying the changes to your morphing body thoroughly.
Your slim, rounded shoulders begin to broaden and thicken, causing you to grunt as the changes travel downwards from your shoulders, making your arms and hands grow bigger and stronger, your fingers and toes becoming short, thick stubs as your fingernails shrink. Meanwhile, your waist thickens out with muscle while your hips narrow, eliminating the feminine curves you used to proudly possess.
You continue to moan as the changes continue, feeling a massaging sensation in your ass as it tightens and firms, shrinking down to a less prominent shape as the fat in your cheeks turns to muscle, leaving you with a flat, yet gropable masculine butt. Your back broadens and thickens, the vertebrae popping into place as your spine shoots upwards, giving you a taller body and a wider frame.
The changes spread downwards into your legs, which bulk up with muscle as your feet and toes grow broader and stronger. Your thighs tighten up, the fat turning to muscle like in your chest and ass, while your calves bulge with strength, making your body and face look weirdly out of place. However, that issue is soon to be rectified, as the soda now takes care of your face.
For starters, your hair becomes shorter and coarser, as it's stripped of its natural, silky smooth texture. Working up your face, your chin begins to protrude visibly, while your jawline grows sharper around the edges. Your cheeks raise themselves higher on your face, becoming more gaunt, while your eyes shrink and narrow as they sink deeper set in your skull. Your eyelashes become shorter and less noticeable. Your nose grows larger and wider, your nostrils following suit, while your lips thin out. Lastly, your forehead broadens significantly, giving your face a chiseled, intimidating appearance. You moan softly as your voice deepens, a result of your neck thickening and an Adam's apple developing in your throat.
As the changes come to a head, your useless pussy lips begin to sag down, joining up together to become your scrotum, your pubic hair moving away from your vagina to cover the wrinkling skin instead. This sac hangs snug between your legs, feeling strangely comfortable. You feel a dull ache in your groin as your ovaries drop down into said sac and change into your testes, your egg cells converting themselves into sperm. Your Fallopian tubes bend downward, turning into your vas deferens. Higher up your body, your cervix seals itself shut, while your uterus shrivels up into nothing. The same happens to your womb, but what is left of it is reconfigured into your prostate. Your clitoris now begins to grow longer and more developed, your clitoral hood enveloping it in a tight hug, changing into your foreskin as your vagina starts to close up, your urethra retreating back inside your body. Once your entrance is completely sealed shut, your urethra reappears at the developing tip of your new penis, completing your transformation.
"ちくしょ…" you mutter out loud, impressed at how you've turned out. While you can still understand English (at least, to some extent), you now speak Japanese by default and understand it fluently. You cup your new phallus in your hand, and your sac in the other, and gently fondle them, moaning softly at the strong, pleasant sensation. After playing with yourself for a few minutes, you think about what to do next.