Japanese by Example
Learning through examples in manga

Following after is bad with あかん

ARIA The MASTERPIECE » Volume 2 » Page 129

Alicia and Akari visit an island that’s modeled after part of Japan back on Earth. There, an elderly local woman tells the two of the fox spirits that visit the human world there. Akari is excited at the prospect of meeting one, but the old woman gives her a warning: on rare occasion, a fox will take a person back home with them.

"The god world and the human world are different."
"Therefore, it is bad to follow along."

やさかい has a meaning like だから.