Should be fine even if it has a known important lesson like the one from the rabbit and the hare (being consistent/earnest/hardworking/perseverant will get you far) or the one from the beauty and the beast (don't judge solely based on beauty). I would say to find a quote you really like and make a story based on that. It's easier to write a story if you have an end goal in mind.
I don't recommend looking for a manga for 'inspiration' tho cause thats an easy street to plagiarizing. Even if ya teacher wont be likely to find out it's still not a good habit to develop. Also, you would end up putting the same amount of effort trying to find something suitable and adapting it for your class
Thank you for your advicee
Ok guys so we have this english project wherein we have to do a one-act play, but the thing is we have to make our own script. I can easily make a script but the story has to have an important lesson. Moreover, it has to have only one setting. Is there any manga that's similar to my description or do you guys have any ideas? Me and my teammates have been talking about it but we have no progress at all