Like Enchanter, Arisa² features a look-alike themed love triangle. However the story is poor and the art is even worse. Yet, if you really desperate to read a series with the theme I mentioned before, you might as well give it a try.
Both series have a non-human female lead who just likes to hang out with the male lead and troll him a little. The male leads in both series were somewhat similar too. If you liked one of those series, odds are you like the other one as well.
My gut tells me you're really going to like Enchanter if you liked Carnivorous Princess Yegrinna and vice versa. In both a non-human girl freeloads at some guys house and trolls him (one of them doesn't do it entirely on purpose though). TBH, I can really describe well why those series are similar (despite the fact that they certainly are), so just trust my gut on this one :)
The only real similarity between those two series is the fact that the male lead has a knack for fixing and constructing various devices (which becomes useful in combat later on). If you think that it is an interesting skill, you should try reading Fate/Stay Night or Enchanter.
Yamaguchi Kumiko is next in line to be the boss of the Kuroda Ikka yakuza clan due to her parents' death. However, fresh out of college, Kumiko decides to pursue her lifelong dream of being a teacher. Now hired as a mathematics teacher at an all-boys school, Kumiko must hide her true identity. She's assigned to class 3D, inhabited by the worst of the worst delinquents. Popularly called "Yankumi" by her students, she tries her best to gain the respect of and offer help to these students who'd like nothing more to make her life a living hell.
What could possibly 3 unrelated series like Unbalance x Unbalance, Enchanter and Gokusen have in common?
In all 3 of those series, the male lead happens to fall in love with a female teacher and in all 3 it takes him a lot of work and maturing to make her feel the same way about him as he feels about her.