The story has no direction. It's that simple, but it's compensated by it's refreshing and vast variety of characters.
The teacher doesn't really have a goal, so neither does the story in my opinion. But the story does have short arcs where we can see her getting closer to her class, and by the end she's practically their second mom. Yay!
This is not to say the story wasn't hilarious at points and that it thoroughly entertained me as we can see through 159 chapters development in all the characters.
Don't expect too much from the romance tag in the bottom although there is a sweet, if very funny confession in the story.
I would recommend this manga as it is very funny, just take note of it's lack of direction
Hopefully you found this useful