Kazusa's heat control, day 7 (part 2) (Patreon)

Kazusa checked the little bottle she found on the floor.
"It definitely looks like the one I drank before, but the color seems just a bit darker.
But... why Sensei had it?
Maybe... afterall, he didn't wanted to stop and brought this for me, but he had to renounce because of his sense of duty as teacher..."

She continued to look at that bottle for a bit without telling a word, like if she was trying to take a decision.

"Still... I don't want to stop! I want to continue to stay with Sensei, so...!"

Took her decision, she removed the cap from the bottle and without any more doubts she drank the content.

"By the taste I can say is the same as before, but this time the taste is stronger and the texture a bit thicker. I wonder what's the difference..."

But didn't took long to understand the difference from the last one.

"W-What's happening? My body is starting to get hot, but is different from when I was in heat... this time is like a fire is burning from the inside through my veins...
Ah! I can feel it converge in my muscles... Ugh!

Overwhelmed by this feeling she closed her eyes and soon the heat was followed by a short intense pain.

"AH! This pain is... is like if I've been lifting some weights many times heavier than I can handle until my muscles almost broke under the weight! Ugh!
B-But... It's starting to feel good..."
The pain didn't lasted long and was followed by just pleasure.

"Anf, my muscles are starting to feel so good... I can feel them... growing??"
The impression was soon confirmed when she opened her eyes and could clearly see her mass expanding under her eyes.

"Anf, anf... this isn't what I was expecting but it's just perfect!
Sensei say that had to stop before he could not resist anymore... but I'll make sure that he will not next time... no... I'll not let him to!!!"

Soon after the growth stopped, but she decided to strike the iron while it is still hot and went to the gym to test her new gains.