A super-powerful nation, the kingdom of L'Arc. Razel, the son of the king but without the talent of Takeshi,
Compared with Kensei's sister and wise man's sister, they are exiled.
Such a lazel is a natural positive,
I'm trying to live as an adventurer in another country,
The older sisters and younger sisters who love him are chasing after me !?
With strong and a little naughty sisters
Flirt adventurer life, start!

The one thing not ordinary about high school student Ryouta is that he has an aspiring manga artist for an older sister. She is so dedicated to her drawing that, despite being 21, she's never really been in a romantic situation. Unfortunately, when she gets her first real job, it's to write an erotic manga. Desperately, she enlists the reluctant Ryouta's help, as a 'model', to figure out how exactly to draw this sort of manga.

The girl, Mana, has no problem with seeing the scenes she plays with her brother as nothing but a hollow reference for her works.... But she fails to realize that her brother seems to become more and more flustered with each 'live performance'.

From MangaHelpers:

Shun knew what to expect when he became a high-school student. As he entered the gates of his new school, four beautiful girls suddenly surround him. These four girls are the same four girls he grew up with since kindergarten. The four girls are Rio the athlete, Miku the cook, Nana the nerd, and Yuri the student president. These four girls will be battling it out between them in order to win the heart of their beloved Shun.

When Konoe Moyako and her little brother, Akira, were young, he said he wanted to marry her. Naturally, Moyako decided that her little brother was a complete pervert who was obsessed with her. Now that they're both teenagers, Moyako is convinced she needs to 'rehabilitate' him. However, it seems that the 'perversion' is entirely in her imagination, and she can't seem to help turning completely innocent situations into creepy ones in her mind!

A heart-warming story of how a neglected orphan, Yuu, has been blessed with the offering of a free wish by a demon, and he simply asks her to become his older sister.

From JShoujo Scans:
Yori Iwatani is close to her 40s and is giving up on love and marriage. She has decided to live a quiet solitary life in her hometown. But when a handsome former classmate appears, things change for her.

From MangaHelpers:
This is the story of a pair of step-siblings who are now living alone together. The high-school-age older sister, Kyoko, is pretty wild (and is even into pro-wrestling), while the elementary-school-age little brother is a fairly serious kid. He is often embarrassed by her teasing. The two of them pass their daily life together, every day cooking for one another.

Jin (female) and Konoe (male) are twins and are just starting their high school career. Jin has always been a trouble to her brother, since she’s very tough and violent, and generally doesn’t behave like a girl at all. Konoe is determined that their high school life is going to be different, and he’s going to make sure she keeps acting cute and feminine. But it isn’t easy for Jin to pretend to be something she’s not…

Tomoki, a high school student lived with his older sister. What happens when a normal boy has to put up with his sadistic but popular sister?

A funny story on the relationship between a not-so-regular pair of sisters!

1) Ane☆Mone Seikaten
A cute and funny little story about a baby-faced high school girl Mone Saeki who inadvertently falls in love with a grade schooler Ren Anesaki!

2) Everyday Treasures

3) Batsu-san

4) Day Dream Believer

From Antisense Scanslations:
Anemone is just like all the other flowers at the flower shop until Akiko, a woman he's already fallen in love with, takes him to her home.

Nagisa Ootsuki shed her former self out of shame from failing her highschool entrance exams. On her first day in her new highschool, who does she meet but the girl who made her fail the exam! How does Nagisa deal with these complicated emotions?

Author's twitter: https://twitter.com/sakuragi_ren

Frio is a best-seller author. However, in fear of his lacklustre appearance and homosexuality being revealed to the world, he keeps his true identity a secret. One day, he meets an extraordinarily beautiful young man named Angel. The two, in spite of all prejudice and discrimination in the world, are undeniably drawn towards one another.

School girl Riko Umekita's life is thrown upside down by scariest boy in her class, Saruwada-kun. His family is from a long line of Yakuza and is known not to mess with them. She is dragged home with him only to find her parents there after some circumstances... Saruwada-kun then asks her to marry him. What is going on?

Troubled by her abusive mother, Shiori is undecided about her future. The only thing she knows is that she wants to always be with her best friend Yukiko. That is, until she sees Yukiko do something unusual one night...

When Shizuka comes back after being away for 13 years, the courageous Kosuke she hopes to find has grown into a perverted total coward. But then again, she had changed a lot too, growing into a true brawling queen. Angel by the infamous U-JIN follows the comedy story of our two heroes. WARNING: This manga's explicit sexual scenes makes it offensive for young viewers. If you still choose to read, do it at your own risk!

Kato-kun (Mr. Kato) is an ordinary boy who works at a convenience store. Extraordinary things have started happening to him since he picked up a beautiful girl at a bar one night. It turns out she is an Angel--literally! She has two wings that sprout from her back, and only a few people can see her. She's moved into his bachelor pad, and he feels like he's in heaven. Although he has no idea where she is from or why she is living with him, he lets her stay as long as she wants. An Angel is a savior--and there are a lot of people who need saving! She crosses the paths of a neglected kindergartner, a troubled middle-school student, and she even helps Kato himself in his attempts to befriend a pretty girl named Miho.

A short oneshot from the anthology magazine, AX. Published in issue 100 from 2014