A group of scattered people who were friends in high school start getting killed one by one, and danger soon follows the heroine, Aihara Kumi, as she starts suspecting that one of them could be the murderer.

V. Koibito no Namae

1. Lover's Name
One night, Ei Ariga the private detective was hit on by an obnoxious stranger whilst out working on a case handled by his father's agency. Then the timid and very polite Ryouichirou, who is a dead-ringer for the playboy stranger, turns up at the agency and tries to engage their services to find out why and how someone is breaking and entering his apartment. Ei-kun discovers that the nasty, violent and annoying carbon copy is called Naruaki and things get extremely complicated when he starts falling in love with both Ryouichirou and Naruaki... Lover's Name is also found in Double Lover - Koibito no Namae

2. Saikou no Kimi
The oneshot is also found in Saikou no Kimi.

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V. Double Lover - Koibito no Namae

2. Kimochi no Yukue
It's been three years since Kirima walked away from his relationship with Kou. Kou's obsessive love was what sent Kirima running in the first place, and now that he has Kirima back he's not about to let him escape again...

From MangaHelpers:
In the near future, aliens from Bluto “invade” the Earth. But what is their objective? To steal all of the timed sale groceries at rush hour and make perverted havoc among the citizens. Not the kind of aliens you would find every day. To counteract this “terrifying” enemy, a special force of heroes, “The First Star Heroes,” has been sent out wearing dynamic colors. But, out of the five heroes, two of them have a secret. Momose Kaname, a 14 year old boy who has idolized these heroes, is transformed into the team’s Pink Hero and now has to hide his identity. And “he” finds out that the Red Hero of the team is actually a girl who has experienced the same gender-bending transformation as Kaname. What will happen to these Heroes, especially Kaname, as they face all kinds of odds during their “heroic” days?

Tachimori Ashita inherited the Tachimori Mansion when his parents died in an accident. Originally owned by his great grandfather, the estate has been traditionally an inn that had many people living in it but, as of lately, it has become vacant due to Ashita losing his parents. As Ashita tries to revive the mansion in remembrance of his parents, he is surprised by a young girl looking vampire named Noi and her servant Sesera who claims to own the place.

According to Noi, she lent the mansion to Ashita’s great grandfather in return for maintaining the building until Noi returns. As a vampire, Noi has super strength, the ability to turn into mist and can cast various spells. She has a powerful dark aura that attracts evil spirits and, because of that, Noi has had to constantly be on the move. But because of that, she has been abandoned by her family and friends. Ashita decides to let Noi and Sesera stay and is determined to start a new chapter in the Tachimori Mansion history.

Dear Sa-chan, if only I’d had sex with you that time, perhaps I wouldn’t have wandered down this disastrous path. A story of true love and it’s downfall, brought to life by an unconventional protege.

1-3) Furachi na Kare no Shitsukekata
Sayuki Isumi, salaryman, got drunk one night because of some trouble at work and bumped into Aya Okimiya, who is one year his junior from university. Okimiya who admired his sempai for quite some time from afar could not help himself anymore and ended up embracing him but can he keep Isumi by his side?

4) Milk Taste Honey
Kaidou-san is a salary man who comes every day to the cafe where Hanabashi Ritsu works. He admires the part-timer from across the room, whose cool exterior entices Kaidou-san. But truly, there is a cute, blushing Ritsu behind the cool beauty on the outside...

5) Welcome to the University of Love
Aizome Riku enjoys napping on the school's roof, but when he falls from a tree tryng to climb down Kairi is there to catch him. The two become fast friends, but Kairi's three bodyguards who follow him everywhere soon grate on Riku's nerves. Can Kairi convince Riku that his 'like' is more than friends and capture his would-be uke's heart?

6) Furachi na Kare no Shitsukekata Extra

Creamy Mami is about a young girl, Yuu, who after seeing a spaceship is given the power to use magic for one year. She is also given 2 cats, Poji and Nega, to watch over and guide her. Using her magic powers to transform into the idol Creamy Mami, Yuu must work hard at acting, singing, helping her parents at their crepe shop, fighting aliens and bad guys, going to school, plus try to get the affections of her childhood friend Toshio.

During the Interwar Period (1925-1932), Tomoji lives in the Japanese countryside while Fumiaki works as a photographer in Tokyo. One day, they meet... This story is inspired by real characters who founded later a branch of Buddhism.

Rather than having zero defence, she pretty much has -10,000!? This self-destructing lewd girl is frighteningly cute! The girl who digs her own graves & the sadistic boy who gets carried away too easily; this is a story about them messing around and their cohabitation in this love comedy!!

Saito Yo has just been assigned to be the secretary of the company's new director, Nabeshima Hisatsugu, who has supposedly "never worked a day in a company" before. Saito is taken aback by the new director's seemingly non-professional demeanor, and he works hard to reform Nabeshima and get him accustomed to the role of director.

A comment Nabeshima makes one day, however, devastates Saito: Nabeshima mentions that Saito wasn't what he thought a secretary should be. Shocked and frustrated, Saito carelessly blurts out while drunk one night that Nabeshima should "take advantage" of his services. From then on, Nabeshima changes his attitude and leaves Saito feeling even more bewildered.

Rin had quit calligraphy after her mother's death. Then upon seeing the calligraphy of a high school calligraphy masters, Uchida Dougen, she started learning again. Rin entered the same school as Dougen and the current calligraphy club or more like Dougen fan club. When the student council president announced that the club would be disbanded, Rin had to take action to keep the club going. Dougen, who had come to support the president, ended up joining the club because Rin's word sparked his interest. Unbeknownst to her, Dougen is somewhat of a playboy. What will become of Rin and her beloved Calligraphy club?

He met a girl. A young girl branded with the mark of a criminal. That was the beginning of everything. "Crap, my girl's so cute" This is the story of the two who became an overly protective guardian and an adopted child, changing relationships, and furthermore until how that relationship evolves.

Girl moves into an "apartment" (seems more like a house with a bedroom being rented out) and finds out the landlady is a lesbian. Being the bubbly cheerful girl she is, it doesn't really bother her, but what will happen when the landlady develops feelings for her and starts coming on to her?

An accidental meeting brought the lonely Su Ye and the perfect prince Zheng Shu together which created brand new feelings. The interaction and feelings between the two were originally familiar made their heart beat. Can there really be a pure friendship between a male and a female?

Keel, the hero of our story, is looking desperately for Siva the so called "best monster fighter" to retrieve something precious that he took away from him, on his search he joins a beginner monster fighter girl, along with her flying pig monster and goes for an adventure to find Siva who for some reason has been missing for two years.

My girlfriend changes her personalities everyday
author's twitter: https://mobile.twitter.com/R_Kitada

The mangaka of Zoids drew the sort of Villainess Otome Isekai story he would like to see.

From Yen Press:

High schooler Ji-Hae is desperately in love with her classmate Seung-Hyu. She has done all she can think of to win his affection, but to no avail. When her latest scheme crosses the line, Seung-Hyu decides he’s had enough…and inadvertently pushes her down a staircase! Ji-Hae awakens in the world beyond, only to learn that it’s not her time to die. But why go back when the love of her life hates her to death? Touched by her passion, the keepers send Ji-Hae to her past life to mend the rift between her former self and Seung-Hyu. But can Ji-Hae keep up the act long enough to find Seung-Hyu and set things right?

Ayame is 14 years old. More than a child, but less than an adult. Ayame is quickly becoming more interested in sex and sexuality and her close friends are facing similar confusion. This is a coming of age story surrounding the rapid changes and challenges of adolescence.

A romcom centered around two childhood friends: Tarou and Umi. It took four tries professing his love, but he finally gets a 'Yes'. Not long after, Tarou finds that Umi only has 100 days to live!