Spoiler free.
I haven't read this series in nearly a decade since it came out. It was the first series I picked up that wasn't rated teen. When I was 17! I even had to wait for the last English book as well that I picked up back in 2009.
I recently re-read it again online and still enjoyed the tale. It is a fun story and a great tale of differences and growing up being different than what society believes is normal.
And if you have apps like Viki I recommend watching the drama done by TBS as they did a great job following the series in its original form.