Start simple, go bigger

First, Haru wanted to ensure that what was done with the book could be undone. But she needed something that was already semi-permanent to test with. So she began to write.

Ann Takamaki has a spray tan

Almost immediately Ann's skin darkened. It looked... Bad, to be frank. Ann didn't even seem to notice. But the plan was to just get rid of it anyway.

Haru's first idea was to use her pen to strike through the text- effectively just crossing it out. As soon as she did, Ann's skin went back to normal.

That was a success. Now it was time to see if the book could do things that were otherwise wholly impossible. She had changed people's clothes and situations, but never something that could physically not be achievable.

Ann Takamaki's breasts will grow 10 times larger she wrote.

In an instant Haru heard a splitting ripping sound as Ann's breasts exploded out of her tank top, sending her bra rocketing off. Her already sizable breasts were now absolutely ridiculous in size.

"Eep!" Ann yelped as she went to cover herself, clearly struggling to do so with how large her breasts had grown. "Ugh! Did they seriously grow again?!" She grumbled. It seemed as though her breasts growing didn't seem unusual to her, but she realized the impact the growth had when it ripped her shirt and bra, leaving her topless.

Regardless, that was a successful physical change. Now she wanted to try something mental.

Ann Takamaki will not be able to think

"Haru, do you happen to have any clothes I could-- duuuughhhhh..."

Ann was cut off mid-sentence as every thought left her brain. Her body went slack, bending forward. Her arms hung limply down, her new big tits swinging. Her eyes were half-closed, as any and every sign of intelligence had left them. Her mouth hung open as drool streamed down onto the patio.

Haru was initially a bit concerned that something like this would be harmful - possibly preventing Ann's brain from doing necessary tasks like breathing. But she was still breathing fine. Haru concluded that the book wouldn't make any dangerous effects happen as an outcome of another, unless it was specified or impossible to avoid. So in this case, while Ann was now completely lacking in any kind of intelligence, her brain was still making her heart beat, her lungs compress, and keeping her generally upright since she hadn't fallen on her face. And thankfully, Haru knew she could just cross these out to fix Ann if she wanted