Higaeri Quest

(from shoujo-manga.com)
The adventure begins with a school girl named Eri getting magically summoned to a magical world. Eri has been summoned by a magician named Rex, intent on doing some scientific research observing people from different worlds. Rex is cute, with long dark hair and a rather pained expression at the trials Eri puts him through. Eri is not your average school girl. Instead of being terrified about her current situation, she manages to secure Rex’s promise to summon her again every week. Well OK, so the promise was rather reluctantly given due to a sneaky trick Eri plays involving the alarm on her digital watch. After all, being in a magical world is a lot more exciting than life as a school girl. The manga series chronicles Eri’s adventures in this magical world, as she travels around with Rex and the Prince of that world, a rather bishounen blond named Krueger. Unfortunately for Rex and Krueger, it is somewhat difficult to keep up with the very pushy Eri, and she manages to get them into quite a bit of mischief.