From Shinnen:

There are rumors of a grand treasure located within the local museum of Ashiwara and that this treasure requires a special key to unlock. But no one seems to know what this treasure is or even what the key looks like.

But Kei and Hikaru, two childhood friends, may inadvertently find out when someone seeks to claim the treasure for themselves and that action plunges their world into chaos.

From Manga Jouhou:
Takashi Sone is living on his own while he is attending college. Out of the blue, his parents tell him that his sister, Mafuyu, is moving in to live with him and that she will be attending a high school in his area.
When she arrives, he finds out that she was kicked out of her old school for getting caught making out with another girl. Soon afterwards, the other girl arrives, having thrown away everything she owns in order to run away and live with Mafuyu.

Volume 11 has a unreleated 2 chapter story at the end called Frills

A collection of oneshots: Story 1: Spring and Love Come Early? Ichio Tomochika, the archery club president, likes the calligraphy club member, Komada Aoba. With black hair and black eyeballs, Komada is just like a stubborn black cat. Looking at such an adorable cat everyday, Ichio hopes Komada can sense his feelings he has for him. After an unexpected kiss from Ichio, will Komada return his feelings? (From Attractive Fascinante) Story 2: The Trap of Love Story 3: I Want A Bit More Love Story 4: Youth Melancholic Story 5: While Numbering Stars Omake: While Numbering Stars Extra

While walking home from work one day, a doctor named Shuichiro notices an angel, Kohaku, stuck on a tree while being attacked by a crow. He rescues Kohaku and, in return, Kohaku offers to grant him a wish. However, Shuichiro is satisfied with his life - he has a decent home, good looks, and a well-paying job as a doctor - so he does not request anything. As Kohaku is honour-bound to grant the wish, she chooses to stay with him in his home, and helps with chores.

From Sweet Lunacy:

Armelia is an orphan girl who sings for work. One day, she met a boy, Luce, and fell in love with him. Unfortunately, Luce was kidnapped by the notorious pirate, Scar. Armelia swore to herself that one day she would rescue Luce. But the truth is not what she thought it was...

*Includes a side story called Haru wa Sakura:

Shou wants to be a doctor, but female doctors are forbidden. Takao is a delinquent, whose bad reputation is known by many. Somehow these two people cross paths and a connection is made. Was it just a chance meeting or will something more come out of it?

[From: InfinityScan] Anna, sweet, kind, and an angel, as Ou Bin describes, was always being bullied by Oc Ja Gang to the point where she has to rest until she recovers. Though, there are these rumor going around the school that Anna is coming back. Ou Bin, excited about the news rushes to go find her but...what he sees is someone else and not the sweet Anna.

From TachiNeko Guild:

Set in post-World War II Japan, this is a story of young Haruomi, an heir of the prominent Morimura family. Stripped of his aristocratic title while facing a repossession of his estate, Haruomi finds himself thrown on the mercy of a wealthy Japanese American, Tsutomu Oshio.

At first, Oshio wants nothing to do with a naïve noble. After all, he hates the Japanese above all else. Yet as the days go by, Oshio finds himself inexplicably drawn to Haruomi’s innocence. Driven by a desire to rid himself of his newfound feelings, Oshio sets it upon himself to disrupt Haruomi’s flawless façade.

Through the hope of saving his bedridden mother’s life, Haruomi accedes to Oshio’s scandalous demands to become his “servant”. Thus, Haruomi’s new life as his master’s plaything begins…

Note: It sounds like the Japanese version of this title included a separate one shot about a host club. While the version published by Enju Group does not.

Collection of short stories:

- Needles and Oranges:
The protagonist believes that she and her female lover understand each other despite a language barrier, but realizes she was wrong when her lover disappears one day.

- A Fun Summer Vacation:
A very short story about two friends who go on vacation together and make an unexpected discovery.

One day, Emi receives a call with a confession to her popular and beautiful older sister. Without thinking, she hangs up. But on the day that she enters high school, by some unknown coincidence she meets this caller who had confessed over the phone...

And thus, an overflowing love begins...

Volume 2 contains the oneshots "Second Bloom" and "An Unrequited Love"

From Wasurenagusa:

A shounen-ai version of the Issun-boushi story. Heikuroo is only as big as a human hand and only in the light of the moon he can gain the normal height. Because people think he is cursed, he leaves his village and goes to the capital, where he becomes a guardian of an aristocrat named Kotohira...

Watanabe, an alien student from 20,000 light-years away, comes to homestay with the Tokino family to gather material for his thesis on Earthling behaviour. He follows around the various family members asking mostly funny but sometimes profound questions about their work, their loves, their polluted air... When he's not being sent on errands or punched in the face, at least.

Yoshiaki is entering a school that is famous for its fights and violence. He chose to go there for just that reason, and he intends to be the strongest one there. When he first arrives, he helps out a girl called Homura, who is being picked on by some guys. When she asks him to be her "sword" afterward, Yoshiaki doesn't know how to respond. Apparently, students of the school team up in pairs; a "sword" and a "master". Others advise him not to associate with the girl, who is a "Rank F", as she probably won't live very long. However, Yoshiake is not thrilled with the idea of abandoning her to die.

Hanamura Masatsugu and Takakura Kuniomi are intimate friends since childhood, and both are heirs to their respective marquises. Their favorite sport is seeing who can score the next bishounen that comes across their path in the Imperial Capital. And now Kuniomi has set his eyes on a new target…!?

Who would be the winner between these two beautiful men’s quest for love—?!

A lavish Taisho* Romanesque edition!! (*** Taisho era: 1912-1926 ***)

From Chibi Manga:
"Does the attractive force make me attracted to you ?"
Sonoko is leading a life of high school girl idly, and one day at after school she "accidentally" kissed her friend's boyfriend in the science room. But Ito, a super A-student, saw the scene!! Although Sonoko hurriedly fled?
This selection of one-shot master pieces describes swinging feelings of teens in love.

This manga is about the boy group in Japan called, Hey! Say! Jump.

A collection of romance stories:

1) Alone in My King's Harem
A concubine falls head over heels for his king. But what happens when the king's ambitions blind him to that love?

2) Night Circus
Hibana, a troubled circus acrobat finds comfort in the arms of another of the circus' performers. But there are more twists to the story than Hibana's aerial acrobatics.

3) The Seabed of Night
A loving servant of a prince lets himself be put under a magic spell in order to spend one cherished night with him.

4) The Adventure of a Canary
A very unusual boy who is owned by an old woman who exploits his talents, and the young stranger who meets him and teaches him about love.

5) Mature Flesh (Michiru Hada)
The rumor "Hidaka will sleep with anyone" has come to the ear of council president. What will the president do about Hidaka?

6) Moist Flesh (Urumu Hada)
Sequel to Mature Flesh

In a post-apocalyptic world covered with water, Wadatsumi, a person who lives in what appears to be the last piece of land, finds a mysterious girl dragged by the waves of the sea. Where does she come from? Are there other lands in this world?

From Taruby:
After 'The Great Sinking,' civilization on Earth crumbled as the world was drowned in the ocean. One tiny band of survivors eke out a living atop the ruined remains of a skyscraper. Wadatsumi, a young tomboy, is saddled with the care of four elderly gentlemen, until a chance encounter with a group of pirates and a mysterious woman turn her world upside-down.

• Harem Days
Madoka Mitsuru (Enman to his coworkers) is a rough ex-yankee, so he's not really sure how he got a job at a prestigious company. He works in "the harem", the name of the gofer department because of all the attractive ladies, under Chief Suzunari, a cheery middle-aged man who doesn't understand the meaning of personal space!

• Hareta Yoru no Hikari (Light of the Clear Night Sky)
Medical intern Chikada Tomoharu is always being called a "nice guy", especially when he's being dumped. When his lover dumps him by email, text message, and he's roughed up by the yakuza outside his apartment building he's having the worst day ever. Building caretaker Fukiage Tatsuru scares the gang off, and he and Chikada become friends. But does Tatsuru only see him as a "nice guy" too?

• Itsuka no Himitsu
It's been ten years since Yuuya was home. That was the last time he faced Asato, the blind neighbor he's always had a crush on. He's spent the time trying to forget the one night he acted on those feelings. But he's been fired and evicted; with no place to go he returns to his childhood home and the man he's never forgotten.

• My Secret: Itsuka no Himitsu bonus

High-school student Kisaragi Maki has one dream: to be a normal wife. She’s part of a Yakuza family known as Group Kisaragi and her father is the third generation of the group - and he wants Maki to be the fourth generation! But Maki isn’t a ‘normal high school student’. She has a split personality which gets her into all sorts of trouble. Can Maki achieve her dream of being a ‘normal wife’?

Includes:

1. Ouji-kun

2. Hare, Tokidoki Yami

3. Kiri no Ie
Suddenly a strange man gives Hayase Nanami, aged 16 years, a package and run away. What will happen next? Will he come back and then...

4. Fukou Sakka to Yobaretai