if you sign up and have an account, you get notified every time someone replies to a question or topic that you're a part of (had replied to before).
It means that the person that says following wants to also know the manga another person wants to know
Example:
Person: are there any mangas that are blah blah..
You: i also want to know that *comments "following" so youll get a notif when someone else respond a suggestion*
Basically its a way to get a notif when another comments what you and the person wants to know
It happens pretty often xD
What does it mean when people comment "Following" sorry I'm. New here