My name is Sato Takahasi, and my mother, Shiori Takahashi, and I have been living together in a house outside of the village of Miyogi, Japan for all of my life. The spring I turned 19, I found a magic plant called the oppahana. The village elder explained that I could dry it and serve it in tea to myself and one other person to made radical sexual changes to the body! I've always been in love with my mother, so of course I served the tea to both her and me. It's now midsummer, and we've been ravenous in our sexual appetites ever since I started serving the tea. If any of the changes get out of hand, I can pray to the shrine god of our village, the one who gifted the oppahana to one man every generation, and reverse anything that grew too much!
I woke up refreshed and ready for a great few days. There had just been a festival to celebrate the solstice, and my mother had made and remade plenty of clothes over the past few days in preparation. She promised we would have another sexual romp for the next couple of days after the festival passed. We shared a room, now, and I watched as she slept. We were our normal selves this morning, but by the end of the day, there were going to be some big differences!
I had prayed to the shrine god during the festival, to completely reset our bodies. I was worried that my mom might be pregnant from all the fucking we've been doing the past week or two, and the village elder said that prayers to the shrine god would stop unwanted pregnancies, as well. Now we were ready to expand once again!
We had promised not to ruin the sheets we used to sleep, unlike the rest of the house, which was still completely cum-stained and trashed from the first time we had abandoned ourselves to our desires. I gazed at my sleeping mother's beautiful face for a few minutes, my penis already tenting the sheets. We don't wear clothes in the house anymore, and I got up naked, used the bathroom in the closet of her room, and went to my old room to get the supply of oppahana.
Another question I had asked the village elder was about consuming the oppahana. "Don't bother experimenting with it, I already have," he said. "Just trust me when I say that brewing tea with it is how you get the most changes out of it." I brewed two pots of tea using only oppahana, and when my mother finally woke up, she came into the kitchen and sat on the floor to drink.
"Are you excited for today?" I asked.
"Absolutely," she said. "are we going to save all the growth for one spurt, or just continue to drink tea and grow all day?"
Quite the decision to make. The tea only affects the body during their first orgasm after they drink it, so we could drink tea all day, resist our urges, and then expand explosively in one night; or we could keep fucking and cumming all day long, getting bigger and bigger with each cup we drink.
"How about, I cum at once at the end of the day, and you keep cumming and growing all day long? Since you got the big spurt when I first served straight oppahana tea, I sort of missed out on any huge growth spurt last time."
"If I recall, your cock did grow quite a bit that night." It's true, but I had only had two cups, while she had had eight. Her growth had been much more fantastic. She smiled, grabbed a cup, and gulped it down at once. "I'm fine with that deal. For every cup I drink, I'll cum. You have to watch me all day long, and match me cup for cup. If you cum before sundown, I get to pick what we do next time. If you make it to the night, you get to pick next time."
How could I complain with such a deal? "Alright, I'm fine with this."
She stared at me, her eyes shining competitively. "Are you sure you can last the whole day without masturbating, watching me grow bigger and bigger?"
"I'll be alright," I said. "Aren't we forgetting something, though? The oppahana tea makes you very tired, and you might not be able to stay awake all day. You might need my cum to stay awake." I'm not sure exactly how it works, but it seems that her cum can give me the energy to fuck a whole day without food or drink, and my semen can do the same for her.
"Okay, then fill this bowl with cum. I'll take sips from it if I get really tired, and you can just drink some of mine if you're tired. If one of us falls asleep, the other person wins the challenge, and they get to pick next time." She handed me the bowl she ate breakfast out of every day. "Hurry up and fill the bowl with cum, I already drank a glass." She began to grab her tits, biting her lip and sliding her naked ass against the floor. Just one cup, and she was already this horny? Why hadn't I just served straight oppahana tea to start with?
We watched each other masturbate, and we finished together. Since I was only shooting out a normal amount of sperm, I only filled the bowl about halfway. "That isn't nearly enough!" she pouted. "Please shoot out more of that delicious semen for me. I need at least a whole bowl of it to last me the day." The one glass of tea had already made some changes to her. She couldn't fit one whole boob in her hand anymore, they were slightly firmer, and her skin was glowing in the morning sun. She wouldn't drink the next cup until I finished came a second time. If anything, her begging and encouraging made the load a bit bigger; some of it dripped over the side of the bowl. She used her fingers to lap it up, and carefully licked it all off.
She drank her second cup of tea, and I caught up and drank my two cups. She came, her breasts growing a bit more, her hair reaching a bit further down, her hips spreading a bit wider, her waist pinching a bit thinner. It was hard to tell how much her ass was changing while she was sitting on the floor. By the third cup, I was feeling drowsy, so I took some of her cum from the floor and drank it, instantly feeling revitalized. She was breathing very heavily by the time she finished her third orgasm. She was lightly sweating all over her body, she was still moaning in pleasure, and cum was dripping continuously out of her pussy. She took my bowl of sperm and drank a few sips, then licked away the cum mustache on her upper lip. "Onto the next cup!" she said.
Fourth cup, fourth orgasm. Fifth cup, fifth orgasm. I was having trouble keeping my eyes open, and I took a few more handfuls of her cum, which was becoming sweeter and sweeter. My cock was achingly hard, but I didn't feel like I needed relief yet.
By the seventh cup, my mom's breasts stretched below her navel. She was still sitting. Her orgasms lasted for at least a minute now. She swayed after her seventh orgasm, and I thought she would collapse and fall asleep. Instead, she managed to grab my cumbowl, spilling a bit on her massive tits, and drank about half of the remaining reserves. She brought her huge breast up to her mouth and licked off the cum there, then stretched her tit a bit higher up and latched her mouth onto her nipple, moaning and sucking and looking beautiful. She must've just been teasing me, there, and I was just about to grab my cock when she released her tit and it flopped back onto her chest. "That feels amazing," she said, "you'll have to suck on my nipples tonight!"
Three cups later, and the changes to her body were almost the same as they were that night she first helped me. I was shaking a bit, now, watching my mother cum endlessly. There was, once again, a steady stream of her cum snaking past her legs and to a slight depression in the ground, where one of the old table legs had stood. It was difficult, but I managed to make two more pots of tea while my mom continued to scream and finger herself in the next room over.
When I came back with the fresh tea, was looking straight at me, her hands exploring every bit of her gigantic globes. "I'm sorry, but I came twice while you were making tea," she said. "I just couldn't help myself. I don't know how you've survived this long without cumming, but I'm impressed." It was just past midafternoon, now, and this second batch of tea would test my limits.
"Should we move to the living room the finish the tea?" I asked.
"That might be a good idea, since it's the biggest in the house. I'll need to go around the long way, go ahead in through the hallway and open the doors for me." she struggled onto her feet and walked to the double doors leading outside. The village elder also said oppahana makes you stronger, but it still seemed impossible to me that my mom could carry such huge boobs without any trouble. I carried the tea and my cumbowl, now beginning to dry, to the living room, and opened the doors there. She was barely able to slide in sideways, her ass squeezing the frame and her bust so big she needed to pull it in to fit. "Okay, let's drink more tea."
Five cups later, and I could barely stand it. By this time in a normal day, my mom would've arrived home and I would be making dinner. My dick was leaking an amazing amount of precum, more than seemed possible for its size. Of course, this was nothing compared to the seconds-long bursts I had when she first helped me, but it was ridiculous. I needed release, immediately.
At this point, I needed to remind my mother after she had cum that she should move on to the next cup. The past few cups, she just ignored me, and continued schlicking endlessly. I let her cum at least three times now between each cup. She had already run out of cum in the bowl for energy, so she occasionally leaned down and licked some of my precum off my dick. Leaning was a very difficult task for her, now, considering the size of her breasts. I could probably comfortably sit on just one boob. Each entire nipple, from the top to the bottom of an areola, was now bigger than her head. She was sitting with her legs crossed, I think, but I couldn't be sure because her tits obscured everything beneath her. A huge puddle of cum was slowly spreading from her, and it now covered a good third of the floor. She was almost completely ignoring me now, lost in the bliss of endless orgasmic joy.
After that fifteenth, cup, I stopped. I was worried about what might happen if my cock became too big; I didn't want it to break a hole in the ceiling! "Mom," I said, "how about you just drink the rest of the tea now?" She was too busy fingering herself still, one hand holding her tits apart, the other reached down between them to rub herself. "Mom," I said again. I grabbed her tit and shook it a litle.
That got her attention. She stared at me for a bit, then came again. I waited it out. "What is it?" she finally asked.
