I would like to see the persimmon tree.

Isn't the cosplayer in the photo a girl?

And I'm not sure if they're 18.

Due to the timing aspect of their abilities, it's complicated. But you're right to be unsure.

The comic is actually very good, I recommend it. The series... well, unless you haven't read the comic. It's not the best adaptation, to put it mildly, and it flushed some characters and their characterization down the toilet. And the style of the original is also quite different.