From Shoujo Manga Maniac:

The very modern tale of a girl named Yun, with a penchant for picking the wrong guys to fall for...and the bad boy, Hiromichi, who may just be good for her after all!

From Obsession:
The students always call him dark, dirty, scary so science teacher, Fuwa Tsutomo, couldn't show his true identity as a good-looking man. Yet he had liked a student, Kurusu, who was failing science. So in order to help and be with Kurusu, even if it's just for a while, Fuwa changed into the "Phantom of Science" and be a private tutor for Kurusu. Unfortunately Kurusu's friend revealed his secret, but still Kurusu didn't care; he only hated Fuwa, not his "Phantom"

In the Lovely Lesson series:

Vol.1 - Lovely Lesson
Compared to other girls at your school, do you think you're ugly? No matter what you try, you never become as pretty as them? Or were you dumped because you weren't pretty enough? No matter what the reason, there is a way to heal you. Meet Yuhri, a "beauty healer" who really is just a high school goods storekeeper. But when Yuhri meets another "beauty healer" like her, Makoto, what will she do?

Vol.2 - Chuukyuuhen
The first story is about a girl who is always called fat and ugly by a cute guy. To make him say she is cute, she tries hard to look pretty.

Vol.3 - Hair Make-Up Hen

From Viz:

Risa Koizumi is the tallest girl in class, and the last thing she wants is the humiliation of standing next to Atsushi Otani, the shortest guy. Fate and the whole school have other ideas, and the two find themselves cast as the unwilling stars of a bizarre romantic comedy duo.

Lovely Complex Plus is actually volume 17 with the final chapter called Love Com Final. The first two chapters are about before Koizumi Risa and Otani Atsushi met each other. The third chapter is about their first encounter and a little bit of what happens to them after the ending of Lovely Complex.

*Contains a side story called Hoshi ni Natte mo Aishiteru (Even When I Become A Star, I'll Still Love You) in vol 12:
Reina wakes up surprisingly in her boyfriend's room. But it seems that she passed away three days ago...

In 2004 Lovely Complex received the 49th Shogakukan Manga Award for shōjo.

Kouji's mother has just remarried, and as a result, he has a brand new father and two unbelievably beautiful twin brothers. In order to get to know his new family better, Kouji transfers to the same private school that his newly acquired step-brothers attend. But when Kouji finally meets them, the two have completely opposite personalities! And it seems like one of them is intent on being more than brothers!?!

Despite his endless enthusiasm and flashy style, Koshiro just can't seem to get a girlfriend or even a date. To make things worse, the cute girls that ignore him all go flocking to aloof Kirihara who glides through life effortlessly and unaffected. In fact, the only thing that Kirihara seems to take enjoyment in is watching Koshiro's failures. Why do these opposites keep getting thrown together or is it more than just coincidence...

This is a collection of short stories by Suihei Kiki that were serialised in the Seasonal Gangan Powered magazine's 2003 Winter issue all the way to its 2004 Winter issue. Ignoring the tame nature of Suihei Kiki's debut work "Mahou Shoujo Rukana", Suihei's "Mika ni Harassment" short stories are extremely ecchi in nature for a manga serialised in a shounen magazine aimed towards children. Ecchi to the point that the compilation in March 2005 was jokingly advertised as Square-Enix's first adult manga.

Mika ni Harassment: In the first story, Mika makes a wish on a mirror in order to change the world into one where boys don't have ecchi thoughts when they look at girls. In the second story, Mika's school falls under the control of a misogynic dog who hates high school girls (which includes Mika). Finally, in the third story, Mika raises the ire of six-year-old child genius, Kokoa, who forces Mika to attend kindergarten again.
Kasumi Otoko no Ko: A story about a girl called Kasumi who is a tomboy. One day, Kasumi's friend, Haruna, gives Kasumi a Chinese doll that supposedly houses an ancient Chinese goddess of femininity. Kasumi drops the doll into a ditch, which causes the doll to seek revenge on Kasumi.
Mahou Shoujo Rukana: A story about a boy named Shuuichi, who has a special power that lets him communicate with animals. One day, Shuuichi moves in with a scientist who wants to study Shuuichi's special abilities. Also, the scientist's daughter is a magical girl called Rukana. Though, Rukana breaks many magical girl stereotypes.

Note: The author published sequels in form of hentai Doujinshi.

Contains two stories:

I. Migiko Nipponichi!! -
As children Sakon confessed his love for Migiko and promised to protect her, but not long after suddenly cut all ties with her. Now, many years later, Migiko is determined to make Sakon take notice of her by becoming Japan's Number 1 idol. - From Solaris-SVU.

II. Takuya of the 7 Wonders.-
There's a rumor in the school that if a person steps into the school at night, they will disappear. Sanami, a middle school student who is oblivious about the rumours, decides to prove those rumors out. She gets her best friend missing and now must save her before she disappears.

From Shoujo Crusade:

In exchange for being the only one who knows his secret, Yuna is tasked to hang out with the quirky student council president... who has a habit of separating from his body and following Yuna around as his soul?!

Mekakushi no Kuni is the story of high school student Outsuka Kanade who can sometimes see a person's future with a touch, and transfer student Naitou Arou, whose ESP is limited to past events. When Kanade glimpses an unfortunate incident coming, can she change it? She soon befriends Arou, who's no novice. While Kanade’s power is limited to the near future and is somewhat incontrollable, Arou’s is permanent and he can even use it to see an object’s “memories”. Are these teenaged seers of the past and future made for each other? And who's right: Arou with his "hands off" policy about meddling in people's lives, or Kanade whose more proactive stance has already had unhappy consequences?

It's the start of high school, and Kako decides to "produce" her bookworm of a childhood friend, Kousei, so that he can become a good-looking and popular school idol. She models him after Lawrence, a character in a manga she likes, but as Kousei's transformation becomes a huge success and he extends his new character beyond what she asks for, what will Kako do? Will she find herself left behind in the wake of his newly found popularity?

---

Also included is a story called Megane Danshi Shinka Setsu (Theory of Evolution for guys with Glasses) in volume four.

A collection of short stories of girls who luv their megane boys~! 1) Bousou?Otome by IKEYAMADA Go High school girl Chihiro is, in fact, a shoujo manga author! She bases her manga on her wild ideas with her first boyfriend, Izumi-kun, but she's keeping it a secret from him...? (Also included in Get Love!! vol 6) 2) Gyutto Shite Chuu by CHIBA Kozue (Also included in Gyutto Shite Chuu) 3) Kimi wo Choudai by KURUMATANI Haruko Himeko-sama who hates to lose actually loves Ren whom she sees as a rival. The Himeko-san in Ren's eyes is...? 4) Kyuukyoku Kareshi ni Yamitsuki Kanojou by SHIRAISHI Yuki Chisako has a boyfriend that's the head of the public morals committee but she has a secret that he must not find out! (Also included in Ojousama no Himitsu) 5) Seitokaishitsu de Himitsu no XX by MAMURA Mio Mayu, who admired the student council president Kanzaki, enters the student council. But as she gets closer to him she finds out for the first time his cold, real face. 6) Megane Jikenbo by NAODA Tsuboko Chiri is always competing with her childhood friend who is the top of the school. Ever since the one time that her result changes, she can't stop her mouth from saying that...? 7) Megane Danshi wo Hitorijime? by HATTORI Miki When Sakurai came early to class one day, she starts talking to guy who wears glasses in her class who also came in early. Bored by his responses, she decides to steal his glasses revealing this four-eyes is actually quite a bishie! 8) Kimi no Heart ni Koi no Ya wo by OTANI Hanayo Akane loves her senpai of the archery club. She happens to confess in full vigor, but the answer is NO!

Abe Maria, an ordinary high-school boy and Nanami Tokuko's childhood friend, is the world's last pureblood vampire!! For 10 years, Tokuko has been encouraging him to become a part of human society, and since then, Maria has come to love humans. As such, Tokuko happily watches over Maria. This couple's story is the world's most gentle vampire comedy.

*Includes an extra story called Manshinsoui no Futari (The Wounds that Cover Us) in vol. 1 detailing a high-school romance between a boy who is suffering mentally and an extremely clumsy girl.

Tezuka teaches about biology in short installments.

From Del Rey:
Junior high schooler Nina is ready to fall in love. She's looking for a boy who's cute and sweet and strong enough to support her when the chips are down. But what happens when Nina's dream comes true…twice? One day, two cute boys literally fall from the sky: they're both wizards and they've come to the Human World to take the Magic Exam. Their success on this test depends on protecting Nina from evil, so now Nina has a pair of cute magical boys chasing her everywhere she goes! One of these wizards just might be the boy of her dreams…but which one?

From Aku-Tenshi :

Because her father was sent to London to work, Natsumi, a 4th grade student, also must leave Japan along with him. Her classmates throw a farewell party for her. Natsumi is prepared to go to London, but on the night before Natsumi's arranged departure, a baby suddenly appears in her house after a roar of thunder! What's more is that this little baby is actually the one that Natsumi will give birth to in fifteen years!

It's about a girl, Taobei, who has somebody writing on her book that she's a pig. This really angers her. Then, there's Muyu, the guy who's been friends with her since childhood... and he's angry with her. A really funny story of a silly and dense girl.

The story of Nanao Shirahane and Kuon Aikawa from Mujihi na Otoko continues. List of Warui Series: Vol 1 Warui Koto Shitai [1-1] Vol 2 Waruiko Demo Ii? [1-2] Vol 3 Kirai ja nai Kedo [2-1] Vol 4 Koi Ja nai Kedo [2-2] --- Warui Koto Bakkashite GomenNasai [1-3 &/ 2-3] Vol 5 Warui Yatsu Demo Ii [1-4] Vol 6 Mujihi na Otoko [3-1] Vol 7 Warui Koibito ja Dame? [1-5] Vol 8 Kare ja nai kedo [2-4] Vol 9 Mujihi na Anata [3-2] Vol 10 Sunao ja nai kedo [2-5]

From Tokyopop:
Yayoi, a spunky high school girl, has inherited spiritual powers from her mother, and she uses these powers to protect people. During a fight with the devil Ura, Yayoi's power turns the devil into a black kitten. Now, even though Ura doesn't hide his desire to "eat" Yayoi's power when he gets the chance, they develop an interesting relationship: the two begin living together, and Yayoi takes her new feline "friend" on her adventures.