Mahou Sensou, Trinity Seven Recommendations
In both anime MC leaves his world to join a magic high school due to a girl magician appearing. Both have great music, similiar character designs, similiar genres.
Both have magican, who is joining magic high school due magican appearence. Both give me similar romance feeling, even thought Mahou sensou doesn't have romance genre- main character is in love with his childhood friend.
The main characters had a normal life until a "magician" appeared. Both animes uses magic. Even though Mahou Sensou(Magical Warfare) does not have the "Romance" genre, it does have some love between them. Both has action genre.