Fatsumoto brushed David's hair affectionately as he nuzzled up against his fat belly, David's hair turning darker and shorter into a more of a short fauxhawk at his touch, while his skin began to turn the same shade as Fatsumoto's and Mitsuhiko's. "Well Debuito-kun, how do you feel now?" Fatsumoto asked him. David, or Debuito, just grinned up at his new father, "I feel very lucky to be your son Otou-san!" He said, the word making him feel all warm and fuzzy inside. Fatsumoto smiled with pride, "Good. You know, I think Mitsuhiko could use an onii-san." He held Mitsuhiko closer to his big belly, the little boy cuddling him happily. "A role model, someone to care for him, and considering how protective of him you are, I think you'd be most suitable."
Debuito blinked, an onii-san? He wanted him to become Mitsuhiko's elder brother? But of course, how could he ever refuse such an offer, surrounded by the warm, smelly steam, making him feel so happy and light-headed. Debuito nodded enthusiastically, "Hai! I'd be honored!" Of course Mitsuhiko had always been his closest friend, it just made sense for him to become his onii-san. Fatsumoto beamed, "Good boy, though of course we will have to make some changes to make you suitable." Debuito looked up at him, curious, as Fatsumoto cleared his throat. Suddenly the heavyset man leaned to one side, lifting a leg, and before Debuito knew it, he was blasted in the face by powerful, stinking flatulence from the fat Japanese man's rear, a powerful gust of steam intensified by the warm haze surrounding him. Now that he had smelled it, Debuito wondered if all the steam in the place was actually daddy farts? Debuito coughed slightly, but suddenly a warm, tingly feeling began to overtake him, and soon he found himself starting to giggle. Fatsumoto grinned, "There we go, you'll be the spitting image of your otou-san!"
As Debuito laughed and coughed, fanning the foul smelling air, he began to feel puffier somehow, more bloated. Opening his eyes, he saw his fingers plumping up, his arm getting chubbier. He looked down to see his arms thicker, and his belly growing larger and doughier. Just like Fatsumoto's. "Woah..." He muttered in disbelief, gripping his growing gut, feeling himself grow fatter. He was clearly still older than Mitsuhiko, but significantly heavier, a real blimp! Like his father in miniature, the fat son of a fat dad. Fatsumoto nodded with approval, "Now there's a boy who can be a role model to my son. A big, protective sumo onii-san."
"I-I'm... so debu now..." Debuito stammered, feeling his big, blubbery belly, his fattened thighs and arms. "I look like a sumo wrestler!" Fatsumoto chuckled, "You are now!" Debuito looked up at him as Fatsumoto explained, "As my son, I'd expect someone who can carry on my legacy as a Yokozuna. Of course the Daddy Dimension has a wrestling division for fathers and their sons! And knowing how feisty you are, I'm sure you'll be as tough a sumo as your otou-san." Debuito couldn't hide his excitement, "Sugoi! I can't wait!" He smiled wide as he continued to grope his larger belly, entertained by the thought of becoming a sumo wrestler himself, someone Mitsuhiko could look up to, a boy who could make his otou-san proud.
"You'll need training of course, but my champion sumo stable is the best in the business. I know we'll make another junior Yokozuna out of you yet." Fatsumoto ruffled Debuito's hair as the boy chuckled, wrapping his arms around his otou-san's belly in a big hug. Though even though he was excited about his new life, some part of him felt like he was forgetting something...