If you liked the The Melancholy of Haruhi Suzumiya anime, the Anime-Planet community thinks you'd like:
After being turned down by his unrequited crush, Hachiman Hikigaya is determined to live out the rest of his high school life single and socially tuned out to avoid the folly of youth. But Hachiman's resolve is lacking compared to his guidance counselor, a woman determined to change the boy's ways. So, much to his dismay, Hachiman is soon forced to reach out to those around him by joining a club dedicated to serving others. Alongside the cold, but beautiful club president Yukino, eager Yui, and other new friends, Hachiman will try to stomach his new volunteer work and survive his ultimate fear: being involved in a typical high school romantic comedy.
A school club, where a colorful cast is unwittingly put together and become a unique set of friends.
Both posses humor, and some high school hi-jinx.
The overall flow of the two series is a bit different, but I would assume if you enjoy one, you will get a kick out of the other.
In both shows MC is a laid back loner that’s not particularly interested in his surrounding and is not a big fan of socializing. Either way, both show feature some club life that soon starts to turn their views upside down. Similar with the cast structure, and with some solid comedy that MCs provide, I’d say that enjoying one may easily lead you to liking the other one.
I know this might be a bit of a stretch, but seeing how Acchi Kocchi is a school comedy with a stoic male lead, I couldn't help but think of Suzumiya Haruhi no Yuutsu. I'm not exactly sure why, but the guy from Acchi Kocchi reminded me of Kyon from Suzumiya Haruhi no Yuutsu. There is also the part about the show revolving around a bunch of his friends. Last but not least, both have a hint of romance. Despite those similar elements the series are not all that similar, but my gut tells me you should try one if you liked the other.
Holding strictly to his family's creed, Kou Ichinomiya has never once, in his life of privilege, owed anything to anyone – that is, until a self-proclaimed Venusian named Nino saves him from drowning in the wake of a dire accident involving Kou's pants. Eternally indebted to the supposed extraterrestrial, Kou moves into her little community under the bridge along the Arakawa river. Ripped from his life of luxury and success, the young Tokyo U graduate now must adjust to his well-appointed hovel, strange new neighbors, and peculiar lover, Nino.
Ko and Kyon are in very similar situations: they are both surrounded by a ragtag gang of everything from aliens to egocentric leaderrs. These two protagonsits usualy find themselves in the middle of abnormal to downright crazy situations, and are charged with fixing them, even when they are not the instigators. Both shows are animated well, have a witty and intelegent script and provide both laughter and the ocational touching moment.
Fifteen-year-old Yamada has just entered high school and is gung ho about achieving her ultimate goal: to have one hundred sex partners! There’s just one problem: she’s a virgin, and she hasn’t even had a boyfriend! To get the ball rolling, Yamada decides to target a shy boy named Takashi from her school; but even though he is also a virgin and she ruthlessly aggressive with her feminine ways, it’s not as easy as Yamada hopes. Though they begin to have feelings for each other, will Yamada and Takashi ever get past first base?
Both protagonists of "The Melancholy of Haruhi Suzumiya" and "B Gata H Kei" are girls who seem to be very lively and fun to be with. They know what they want and sometimes they don't care about other peoples feelings when they try to achieve their goals.
Somehow they also seem to like ordinary boys as their victims... :D
Birdy Cephon used to be a butt-kicking intergalactic Federation investigator who took down bad guys where they stand; Tsutomu Senkawa used to be a normal student with shy tendencies and a penchant for exploring abandoned houses. However, when Birdy accidentally killed Tsutomu while trying to apprehend a famous criminal on Earth, Geega, both of their lives changed forever! Now, while Tsutomu's body is reconstructed in a faraway place, the two must share the same body – Tsutomu controlling it by day, and Birdy taking over when she spots a criminal in need of tough justice. All Tsutomu wants is to live a normal life; can he manage to cope with Birdy's enormous eating habits, intense muscle use, and easily irritable attitude?
Both of these series feature a strong female lead character with a weaker male partner. The plot involves supernatural occurances in a high school situation. The plot in both also leads towards one character potentially destroying the earth.