Okay, you know what the grammar mistakes were: capitalizing 'she' in dialogue tags even though it's not a proper noun, and doing stuff like, "Hi." She said instead of "Hi," she said. Honestly, that was probably the only bad thing in this oneshot.
It was kind of corny; not the present but the flashback, and I liked the present part much more than the non-flashback part, especially the beginning and the very end.
her sapphire eyes]
Just...try blue.
You always carry yourself in a way that says ‘Don’t fuck with me. I’ll own your ass in a fight’.” ]
The period should be inside the inverted quotation marks, not outside them.
Really, I liked it. So there. 8D

Hello, Bluey. Sam here.

You didn't confuzzle me in any way, shape, form, or fashion. (I stole that line from my fifth grade teacher.) I like it, and think that it was cool how they changed.

Hehe, you didn't confuse me at all. It's so weird that how their roles were reversed in life.