As the two girls walked along, Luka was completely absorbed with what she should use to test the stone. Of course, Mayuri was skipping a little in front of them. This caused her rather large chest to bounce around in front of her, almost taunting Luka. She had always wanted to be a bit bigger up front... She was a bit sick of having people almost mistake her as a dude from far away. Even up close, nobody really seemed to be able to tell. But, if she was a little bigger, that wouldn't be a problem anymore... So, with that slight thought floating across her head, she made up her mind. Steeling herself, she made her wish.
Luka: I wish my chest was as large as Mayuri's.
Suddenly, she felt the world spin around her. She got dizzy, and stumbled for a second. Mayuri paused ahead of her, and looked back, confused. When the dizziness finally faded, Luka slowly lifted her head, her eyes still shut, prepping for another wave, that never came. But still, something felt off... She felt... heavier. Realization dawned on her as she slowly opened her eyes. Sitting there on her otherwise perfectly thin frame, were two large orbs. Boobs. She had boobs. They were fairly large, matching Mayuri, but looking ridiculous on Luka's smaller frame.
Mayuri: "Luka-chan? What's wrong...?"
Luka: "Wha..."
Then, the words on the note stuck out in her mind:
You can altar the world and yourself, and only you will know.
This must be what it meant. She had changed her bust massively, but Mayuri was clueless. Not that that said much, but Luka knew that even the oblivious Mayuri notices more than people realize. Surely she would notice a change this massive... if she could.
Luka: "I-I'm... fine."
Mayuri: "Hm... Mayushii thinks that's a lie... Oh, you're probably dehydrated! We need to get you to the lab, quickly!"
With that, Mayuri dashed off, and Luka followed her hesitantly. pulling out her phone as she did so. Looking back at past pictures, it looked like she had grown to be this size over the last year, mostly exploding in the last month or two. It had gone so smoothly, making herself bigger. And she felt more powerful like this, too... but what else should she do? She should probably be careful with it...