In the Koi Nanka Shitakunai series:

V.1 - Kyou kara Kyoudai ni Nari
When Nakajima's mother decided to remarry he was afraid but everything turned out to be even better than he expected. His new older brother helps him and spoils him a lot and they're getting along very well until the moment when Nakajima comes home earlier and sees his big bro playing with another guy in the bedroom. What's gonna happen from now on?

V.2 - Kyou kara Koibito ni Narimashita

From Anime News Network:
The story begins in the distant future in the far reaches of the galaxy. The Human Galactic Alliance has been constantly fighting for its survival against a grotesque race of beings called "Hidiaazu." During an intense battle, the young lieutenant Ledo and his humanoid mobile weapon Chamber are swallowed up into a distortion of time and space.
Waking from his artificially induced hibernation, Ledo realizes that he has arrived on Earth, the planet on the lost frontier. On this planet that was completely flooded by the seas, people live in fleets of giant ships, salvaging relics from the seas' depths in order to survive. Ledo arrives on one of the fleets called Gargantia. With no knowledge of the planet's history or culture, he is forced to live alongside Amy, a 15-year-old girl who serves as a messenger aboard the Gargantia fleet. To Ledo, who has lived a life where he knows nothing but fighting, these days of peace continue to surprise him.

The story revolves around a high school student named Shinya Matsumoto and his love story, which takes place in the summer vacation. Shinya unexpectedly encounters a car accident, which results in a mother and son being taken to a hospital. The son, Daisuke Kirishima, is completely fine while his mother, Reiko Kirishima must stay in the hospital for three weeks and is unable to look after her son thereafter.

A freshman in college, Amano, is taken a liking by a mysterious senpai, Kamishiro, who raises chicks. When Kamishiro hugs him out of nowhere in their first meeting, he thinks this senpai is crazy, but as he spends more time with him he sees how kind he is. But one day, while Amano is playing with the chicks, Kamishiro kisses him out of nowhere! An airheaded research student and a kuudere freshman's love story.

Hokuto Kuzuhara is a delinquent known throughout Sekai Private Academy. His way of life being so hated by his family that they give him an ultimatum: find a girlfriend within a year or move out. That said, though, months pass and he still has had no luck and it seems like he never will. It is then during this predicament that he is approached by the student council vice president with a plan that would both save him from moving out... As well as help her with her revenge.

Hito Natsu no Kids Game (ひと夏のKIDSゲーム Hito Natsu no KIDS Gēmu) is a short, debut manga work by Ken Akamatsu, the creator of Love Hina. The manga was published on September issue of Kodansha’s Magazine Fresh on September 10, 1993. Ken Akamatsu later received Kodansha’s "Freshman Manga Award" (Japanese: 新人漫画賞/少年マガジン新人賞) and Special Jury Award (Japanese: 審査員特別賞) for this work.The manga was re-published on 20 May 2001.

(Description taken from Wikipedia)

Mamoru is a Nishiarai game player who has switched to a first-class powerful new high school named Hijiri Gakuen Koukou. There he met with a group of eccentric game lovers who call themselves Dennou Kenkyubu, he accidentally joined and had to undergo a variety of events and adventures with them.

Story of Hatta Shuuji's encounter with problem-child and popular model Haru. Incidentally Shuuji is the childhood friend and ex-housekeeper of Maruyama Mie.

Spin off of Hitsugi no Chaika. Takes place in high school.

From Winter Translations:

This is a story about a pair of twins who're, undeniably very different from one another. Big brother Shuuya and little brother Yuuta are basically light and shadow...

Rika is known to be a cheerful girl, but is that her real self?

From Loveless' Site:

Amidst the crowds in Asakusa district, Tokyo, a young man is assaulted by a group of bandits. When a red-haired stranger comes to his rescue, Suoh falls in love at first sight, but all's fair in love and war.

Li Xao Yao left S.W.A.T to become an ordinary security guard, while working, he happened to enter the VIP room and found Lin Wan Er still in the middle of changing, as revenge, she took him on a ride and kicked him out of the car. After hours of walking, Li Xao Yao finally managed to get back home just to be kicked out of the house. He then got an offer from his previous supervisor to become the bodyguard of the Tian Xi group ceo's daughter both in game and in reality. But unknown to Li Xao Yao the girl was actually...

Madam Misa dies mysteriously at the Saturday Night Club. Soon after her death, her young handsome and broke host Hideo opens a similar looking "Host" Club of his own. Where did the money come from? Did Hideo have something to do with Madam Misa's death?

From Sura's Place: Regarding R is the stories of four women who are friends. All four women have problems of their own. One just wants to be loved. One wants to find what she is living for. One wants to have a good career. One wants to just move on. While they are "friends," they don't always get along and you will get to see their dark sides.

Hime Arikawa is a high school boy with a huge debt, and he is saved by the girls of his school's student council after being chased down by yakuza debt collectors. The student council agrees to pay off his debt if he'll join the student council and spend his high school life cross-dressing.

Mi Ju, the most beautiful cosmetic model of CF, and her school friend Yu Jin, are thrown to the past where at that time people's opinion about beautiful woman are different from nowadays. Mi Ju who is loved by her beauty and body height, in those times was considered as 'ugly woman'. They must find ways to get back to the future if they don't want to live in those times forever.

Five years ago, Hokazono Akari died in an accident. Now 23 years old, her boyfriend and childhood friend Shiki Daichi still hasn’t found closure. While he chases after memories of her on the earth below, she uses every tool at her disposal in heaven above to force him to forget.

Long ago, in the far reaches of space, there existed a world as pure and blue as the Earth. And on this world, there lived two "Queens" with the power to control it. When the world is thrown into chaos by one of those queens, a young boy and a young girl must stand up to challenge her for the sake of protecting all that they hold dear.

Note: TSP is using the tankobon chapter numbering (where ch. 12.5 is ch. 15-17 in the magazine raws) compared to groups who previously used the magazine raws.