User blog comment:Bennia Lover/Age of Characters/@comment-1359322-20170509003546

Just want to throw in something really important for you regarding Rose.

"“Of course….. Despite my appearance, I have already graduated from school in my homeland by skipping grades. Even though I’m still young in age, I am qualified to teach students.”

Seriously? She doesn’t appear to be older than us at all, but she chose to become a teacher."

- New Life

"Her setting age is 17 to 18. Even though she is young, she chose to become a teacher instead of being a student. So that will make it compulsory for her to go to the school trip. This is the birth of Rossweisse-sensei!"

- Volume 7 Afterword

Well good luck explaining this.