If you're looking for anime similar to Magical Sempai, you might like these titles.
Ichiro Sato is about as average as a student can get… except for his above-average ability to land himself in totally awkward, intensely risqué situations with his no-nonsense teacher, Kana Kojima! Ichiro has his hands full dealing with these steamy shenanigans and unexpected encounters in the most unlikely places. At least it can't get any worse, right?
Both series are short, echi comedies with a lovable cast of characters. They get into fairly unusual, if not impossible, circumstance leading to hilarious situtations. These both are perfect to get your echi fix in a short period of time.