Asakura Kosame is rejected by the girl he likes. He bought a guitar and created a song solely for the confession on his graduation day in Junior High. Unfortunately, the girl likes another cool boy from another school, whom happens to be a member of a band.
Later, Kosame enters Meirou High. He decides to join a music club and become great to show it to the girl whom rejected him for revenge. But, it turns out there is NO music club at Meiro. The one who sees him at that time is...

In the Pretty Babies series:

Part 1 - Pretty Babies (1 Volume - Complete)
Rookie detective Chikara has been assigned to the close minded, hard-faced senior detective Ibuki, One day, Chikara, who had tailed Ibuki in order to uncover his secrets, witnesses Ibuki carrying a suspicious heavy bundle out from a church. Then, after almost being run down by a car, Chikara is asked to spend the night with the beauty who'd been driving in lieu of compensation...?!

Part 2 - Heavy x Beauty (3 Volumes - Ongoing)
In the middle of the night, Ibuki suddenly calls on his superior Kiriya. Both work at the Metropolitan Police Department and have been dating each other for the last three years. One day, Kiriya's uncle proposes to headhunt Ibuki, and talks of Kiriya's own arranged marriage introduction.

"Hmm, I guess it's high time." Kiriya sighs upon receiving a phone call from former bad company...

Dong Nu was an ordinary beautiful girl in her junior year of high school. After an accident, she met a very powerful yellow-haired man. Although his behavior was a little eccentric, he attracted her attention. As she learned more about him, she began to discover that this man had a shocking identity, as he was not just an ordinary mortal... In fact, you might even call him a... Original Webcomic: http://ac.qq.com/Comic/comicInfo/id/524373

After her mother's death, high schooler Mi-Hyang packs up her belongings and enters the household of her mother's formal manager. Even though she was a daughter of a rich man, with her father and other family members still alive and well, she apparently has good reasons for doing this... So the life of smiling 24/7 Mi-Hyang and the two good-looking sons of her mother's formal manager -- with their own set of unique personalities -- begins!!

The women in the Chidori family have the reigns firmly in hand. Then a cool young man appears among them as the mother's new assistant.

From MangaHelpers:
Maiharu Hiromi has moved from Nagasaki to Kamakura at the start of her high school years. Kamakura is a beautiful, mountainous place, with a view of the sea and Mt. Fuji, and Hiromi is thrilled to explore the area. Hiromi hasn't ridden a bike since she was very young, but she attempts to ride to her first day of school anyway. In her case, riding a bike does not come naturally, and she ends up bumping into her first friend, Tomoe, who helps her learn how to ride. It turns out Tomoe is going to be in Hiromi's class, and their teacher is also a cyclist. Now Hiromi's exciting high school life, full of new friends and learning about cycling is about to start.

Izumi Seita, a gay, introverted, and pessimistic high school student, falls in love with Shinoya Toichi, his best friend. Shinoya is the complete opposite of Izumi. Before Izumi leaves for university, he gets his only chance to hold Shinoya. The sex they had seemed like a dream, but Izumi absolutely refuses to ruin his friend’s life and decides to try and forget about his feelings, even though it makes him miserable. But Shinoya won’t accept his decision…

Tamami-san is a bakeneko, an immortal cat-human, seeking revenge on all the descendants, to the seventh generation, of the man who scarred her for life. But to hunt down those descendants, she needs money. For money, she needs a job. Days in the office, nights out hunting. No wonder she can't stay awake!

Having given a magical Tengu mask to a human boy when she was little, Tengu princess Arazunaya Jirou is told by her father to go get it back. Nariyuki (the boy), now a high schooler, doesn't want to give it back. Slapstick comedy ensues.

From AOC Translations: A fast-paced heart pounding, and dangerous sonic love story!

Hina is busy managing the Apricot House in place of her father, but Anzu, the strange boy who lives in room 304 is quite the troublemaker.
One day, Hina accidentally breaks Anzu's keyboard and instead of asking Hina to pay for the damages, he asks her for favour after favour after favour! While this goes on, Hina discovers that Anzu is actually the charismatic vocalist for a super popular band!!! Is the lame weirdo that Hina knows the real Anzu? Or is the cool guy on stage? Hina's everyday life is changing rapidly.

From Paper Dolls Project:

Instead of her father, Hina is the one running the duties of the Building Manager in "Apricot House". One day, she accidentally destroys the keyboard of Apricot House room 304 strange resident. Hina is then asked by this strange guy to run errands for him as reimbursement. In truth, the strange guy residing in 304 is the charismatic vocals of the popular band ...... What will be his true face!? Chicks usually will change rapidly in the face of a cool stage -! Slowly, the world that Hina knows is changing. Experience this speed ​​of sound love story!

I Love You yori Aishiteru (I Love You More Than "I love you")
Honour student meets delinquent, and an unusual relationship begins.

End-of-volume extra: Onaka wo Sukasete Kaettekuru Ne (Come Home Hungry)
A crybaby who always gets picked onto sports teams because of her height but can't score to save her life, and her cool-headed childhood friend from the cookery club.

Masaki Masamichi has his heart set on joining the legendary manga club of Takidani High School. After all of his effort to get into Takidani High School and prepare for his club entrance, he finds out that a horrible change has happened to the club of which he dreamed. How will he cope with the disappointment of learning that his long-awaited club life consists of drawing ero-manga?

Junko Sakuraba, a 27-year-old lecturer at an English conversation school has no boyfriend. Her parents set up a marriage interview for her with a man who turns out to be a Buddhist monk. However, Junko has no intention of becoming a temple wife, so she refuses to do the interview. Soon afterward, the man signs up to become her private student.

N/A

Madoka is surprised to discover that her parents have won a 100,000,000 yen (one million dollar) lottery. To make things worse, they inform her of their decision to pursue their lifelong dream of becoming doctors. What will happen to Madoka who, when deciding to stay behind, is left to fend for herself in a family acquaintance's (the Asagi's) guest house?

Includes:

1-3) Dreamers High
Ikuya is not interested in having a girlfriend or boyfriend. Ikuya's childhood friend Kishi just started going out with a boyfriend much older than him. Ikuya feels jealous of Daichi not because he's in a relationship, but because Daichi looks as if he's shining with happiness. But one day Ikuya accidentally saw Daichi and his boyfriend in their bedroom?!

4) In This Colorless World (Kono Iro no Nai Sekai de)
Miyamoto Kano presents the story of an ex-gangster and an elite office worker! "On the first snow day of the year, I let an outrageous man come inside. Inside my room, my body, and my heart."

5) Until the world ends (Soshite Sekai ga Owaru made)
Continuation of ch 4

5.5) Dreamers High Extra

--
Part of Rules / Hydra Series ?

Mysterious murders have been taking place in town lately and everyone is uneasy. Anne may look like an ordinary teenage girl in plain human’s eyes but she has something unique that attracts Vampires. May it be her blood type or even something in her skin that makes vampires so attracted to her? No one knows... One thing is for sure, Vampires keep coming in the city she lives in and they are even in her school now! Luckily for her, she has her brother to protect her and also one mysterious new guy...

Yurim Han has just been accepted to the exclusive Yusung High School, known for its high standards. Expecting that, she is still shocked by the level of excellence. Every student around her is a freakishly gifted genius! It's high school life on cognitive enhancement drugs. Can Yurim survive in such an environment?

The demon king has awoken after his 500 years long slumber and he tries to destroy mankind. Now a little monk has to travel to look for 12 warriors with powers of the 12 Chinese signs to fight him.