I have a couple updates from this Chinese Web Drama Monsta X will be in. It will air on the 25th of this month but I'm still not sure where we would be able to watch it with English subs. Sorry Guys! BUT! I have this video below telling you a little more about this drama and what it will be about! I also put another video down below that one and that's Monsta X's OST and MV! I honestly think the MV shows a lot more of a preview and info about this Web Drama. So I encourage you to watch it if you're interested.
Goodnight Teacher Chinese Web Drama Info Video
Goodnight Teacher OST [MV]
《My Love - Monsta X》
(NOTE: Changkyun, I.M, isn't in this ost but I'm not a 100% sure but I think he will be in the drama since he is promoted on the drama pictures.)
Thanks to @PrettieeEmm we now know where this drama is going to be aired! Check Comments for more information!