Daichi Shinigawa is a typical delinquent who wants nothing to do with high school. However, bespectacled Hana Adachi, the class representative, will do anything in her power to make sure Daichi participates in whatever events the school has to offer. If she has to surprise him in the boy's bathroom to get him to go on the school field trip, so be it! Daichi is confused as to why a class rep would care so much about a troublemaker like him; what could be the reason behind her actions?
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.
In both titles the main heroine is very energetic and passionate, daughter of the yakuza household. They try to live a normal life without employing the powers of their families. Both are very strong fighters, but try to avoid fighting as much as possible.
In both cases manga deal with deliquents, changing their ways for one reason or another. Both are very good school life stories with lots of comedy mixed in.
Haruna has never been feminine; she was the star pitcher of the softball team in middle school and didn't focus on relationship, but now that she's in high school she has a new goal: to have a shoujo manga-style relationship. While Haruna tries to be attractive and get a boyfriend, she has no idea how to accomplish her goal; and thus, she recruits the reluctant Yoh as her coach. Yoh is very attractive and dislikes women and the problems they cause, but is impressed by Haruna's determination and agrees upon one condition: she promises not to fall in love with him. Thus begins the crazy relationships of Haruna, Yoh and their friends as they all struggle to find themselves and their true loves.
Both manga feature a girl who is clueless about how to be a normal high school girl. The male protagonist is dragged into helping her out and ends up getting more than he bargained for. Both are funny with nice romantic moments.
Both are hilarious stories about a delinquent who starts out with almost no friends and a bad personality, but change (somewhat). They also have hints of romance throughout the story. If you liked one, then you'll probably like the other.
President of the Student Council at the almost-all-boys Seika High School, the hard-as-nails Misaki Ayuzawa works every day to make life easier on the small population of co-eds who have enrolled there. Though an unholy terror to all things male during school hours, in order to provide for her impoverished family, she secretly works after school at a maid cafe in Akihabara. However, when campus hottie Usui Takumi wanders into the restaurant during her shift, suddenly she finds her reputation in school at his mercy...
Both Kaichou wa Maid-sama and Yankee-kun to Megane-chan are about hard working high-school student councils. One is a shojou manga while the other is a shonen one, so the style does differ, but if you enjoyed one of these you will probably like the other too. I mean both have bits of comedy and romance, what's not to like?
P.S. YtM starts off weak, but gets better around volume 2 with introduction of new characters. Because of that the resemblance is not obvious from the start.