From ShoujoMagic:

Miu Sakurai, age 15, attends a Catholic school where she prays every day for her admired Shion Amamiya to return her love. When that doesn't work, she places her faith in a book of magic and tries casting one of its spells. However, it's not love that manifests... it's Satan! "The recompense for the contract to grant your wish is your virginity," he tells her, and this is Miu's virgin crisis!

Vol. 4, Story 2: Satanic Honey
Malphas, who exists on Earth as Tsubasa, meets a young girl named Manami who has an unusual compassion for crows. She has two secrets which will transform Tsubasa's reasons for wanting to mature into a full demon...

Vol. 4, Story 3: Satanic Cohabitation
The continued adventures of Miu and Satan. Baal, who desires Satan's place as the Lord of Hell, kidnaps Miu to use as Satan-bait. But complications arise when Baal looks for the aspect of Miu that would attract a high-level demon... and finds it!

From Shoujo Manga Maniac: Ruka's a junior high student in love with her father's assistant, Fumi-sempai. She wants to become an adult quickly because everyone sees her as a little kid! But what would happen if she actually became an adult with the help of a time machine?

From ShoujoMagic:

All Kumiko wants is to become a teacher; however her father is dead set against it. He is giving her one chance to prove herself as a teacher before forbidding her from pursuing this career forever. Meet her newest student, Ryu-kun. He has NO desire to LEARN anything from his tutors, rather he is an expert at teaching THEM about...SEX?!

Note: The story was originally released as a single short story, but it later became a series.

It's a story about a girl who lost her every memory. One stormy night, a sudden meeting changes her life forever. She starts anew while still trying to set the pieces of the puzzle that was once her life. Soon after, a love that puts everything on the line is born in the girl's heart.

By chance, she starts living with a boyband called RISKY and her adventure of love and discovery begins...

From ShoujoMagic:
Shinjo Mayu's newest leading lady is an idol, and the leading man is... a future prime minister!? Just what is a "Love Celeb"? Nakazono Kirara is an aspiring starlet. She used to think she'd do whatever it took to get a starring role in a drama and have a CD. But her manager, Hanamaki, proves her wrong when he sends her into a room full of horny producers to sleep her way into a role! Kirara wants no part of it! She's a virgin, and these guys are scary!! Especially the silver-haired one named Gin... He seems to be in charge. But he lets Kirara leave the party with her virginity and his phone number, and it seems like nothing lost, nothing gained... until Kirara is suddenly the most famous new starlet for no apparent reason!?

Side story in volume 7: Darenimo Ienai!
Ruka’s a junior high student in love with her father’s assistant, Fumi-sempai. She wants to become an adult quickly because everyone sees her as a little kid! But what would happen if she actually became an adult with the help of a time machine?

1-3. Goshimei desu!
Renjouji Kiriya holds the coveted position of the number 1 ranked host at a high-class host club "Chateau du Amour" in Tokyo. The Chateau du Amour specializes in providing the company of beautiful, cultured men to female customers. Few people know that the popular Kiriya is actually Yamada Kotarou, a boy from Nagasaki who came to Tokyo to find a way to repay his parent's debt.
Some of the other hosts, jealous of his position, are determined to get past his perfect facade to discredit him. Kiriya will have a hard time stopping them, especially after a former customer dumps an adorable 5-year-old girl on him, claiming he is the father. The only thing that could make this situation more difficult would be the arrival of his Nagasaki girlfriend Miharu, who knows nothing of his career as a host...

4. Apple!
A kind-hearted guy who grows up eating cakes and whose parents own an tartlet cafe, wants to be the ultimate gang leader. A villainous girl who was brought up in a family of gangsters wants to be the owner of a tartlet shop! How will the pair cross one another's path with their dreams of the opposite party?

Akira Shiraishi, a young high-school boy with feminine features, joins Blaue Rosen, the all-girl band that Mizuki Sakurazaka, an androgynous girl of the same age, performs lead electric guitar in.

Their high-school life is anything but typical: Mizuki is the "prince" of her all-girl school while Akira is the "princess" of the neighboring all-boy school. A series of comical events brings them closer together, even as the prejudice of the people around them tries to hold them back.

[From ShoujoMagic]: A collection of short stories from the pages of Sho-Comi! Story 1: Side Seat de Daite. Mamii is in love with Sawaii, the person everyone considers to be a dork. When she confesses to him, he tells her he has conditions for dating her. What are the conditions? And is Sawaii the person she really thinks he is? Story 2: Brazen Lovers. three chapters Yuuna's mother moves them everytime she breaks up with a boyfriend. This new place is a real dump. Annoyed, Yuuna heads off to the beach where she meets a very sexy guy. Sou says "Lets always be together." but when Yuuna wakes up he's gone! Two people like this are bound to meet again... Story 3: Feel It, Roast Virgin. Rika is a virgin and is very nervous about her first night with her boyfriend Yuuya. It doesn't help that Yuuya tries to do it everywhere, outside, at school, he's ready! But will Rika be ready? Story 4: St. Gal Chick Valentine's Day. Mika's school has separate buildings for boys and girls and the girls have asked Mika as a student representative to get them co-ed classrooms so they can spend Valentine's Day with school idol, Subaru. Mika vows to try her hardest, even though Subaru annoys her. But maybe he's not such a bad guy. Story 5: Secret Apple. Sakura Kazuki and Katou Ryu are lovers who have been meeting secretly for two years. Because they were once step siblings, and their parents had a messy divorce, they can't tell anyone. Will they ever be able to love freely? Story 6: Double Face The Dangerous Classmate. A short 6-paged funny.

Note: Because Shinjo Mayu stopped her job relationship with Shogakukan, she continued her incomplete manga in Asuka and called it Ai Ore! - Danshikou no Hime to Joshikou no Ouji This can be considered a continuation of Ai (w)o Utau Yori Ore ni Oborero! or even as a second series.

1. Midara na Senritsu Hiwai na Yubisaki (Lewd Melody Obscene Fingers) by SHINJO Mayu
Yurika has grown so used to doing what others tell her to do that she never realized she was like a caged bird. She accepted it as a matter of course when arrangements were made for her to get engaged to Satoshi, her controlling piano teacher. That is until piano genius and fringe element Hibiki teaches Yurika how to put emotion in her music--how to fly from her cage--among other less innocent things...
(Also included in Motto Oshiete)

2. Hyoutenka no Maria by MINAMI Kanan
A story about a girl named Miona who saved the drunken university student Rikuya from freezing to death. To thank her, he takes her to an amusement park... they get along very well and Miona kinda fell in love with him. Next day she sees on tv that a female student from the same university as Rikuya was stabbed... and she begins to think that it was him...

3. Abunai Houkenshitsu (Dangerous Health Room) by AYUKAWA Mio
Fujimori-sensei has a secret that involves the health room. Could he be meeting someone there...!?

4. S no Junjou M no Yuuwaku by KOUSAKA Yuuka
Yuu is in love with Makoto, only to find out that her mother is engaged to Makoto's father. Now she must live with Makoto, and his equally handsome twin brother.

5. Kare no Taion Kanojo no Toiki (His Body Temperature Her Long Sigh) by ASAMI Miyabi
Yukina is on the same committee as Narimiya. She notices the cologne that he is wearing and stares at him sadly. Could the fragrance be the cause...!?
**Also included in Kedamono Shounen Shoujo

6. Kakusei Full Moon (Full Moon Awakening) by YUUHI Ryuu
Yuzuki and Takara are childhood friends and so close that people consider Takara to be Yuzuki's girlfriend. But it's all in good fun--because Yuzuki is eighteen and Takara is only thirteen. Now that Takara's body is maturing, though, the joke isn't as easy to brush off as it once was...especially with a full moon pulling Yuzuki's desires to the surface.

7. Tomodachi Ijou x H Miman (More than Friends, Not Up to Sex) by USAMI Tae
Making a confession is the most difficult part in a love relationship. Follow Miku in her way of saying "I LOVE YOU TEPPEI".

This is a manga with several oneshots.

Story 1: Pure Love Strip
Story 2: Beautiful Beast
Story 3: Morning Waking Kiss

Story 4: Daisy by AMANE Yuko

Story 5: Lustful Darling
Story 6: Love Princess and W Prince
Story 7: Yokujyou Nyan Nyan (Alluring Nyan Nyan)