From Aerandria Scans: My mama is in heaven, but...I have my big sister!! Hinako is a high school students who has a lot of things that she wants to do, but for her cute little sister, she will become a mother!
Onee-san no Jijou (Sister's Situation) is about a 16-year old high schooler named Tsukiko. She has a crush on a guy in her class, who is also a popular rookie soccer player named Kou. The thing is, her mom just got remarried... to Kou's father, making Tsukiko and Kou step-siblings.
From Aerandria Scans: My mama is in heaven, but… I have my sister! Hinako is a high school student who has a lot of things that she wants to do, but for her cute little sister, she will become a mother!
Collection of oneshots.
From Chibi Manga: She was part of a Band. She wasn't interested in love but…
Annually, the inhabitants of a particular mountainous settlement conduct a festivity rejoicing the bountiful harvest. Tominaga Yuuki, a 17-year-old who originates from somewhere else, is designated to portray the purifying agent's character in the Oni cleansing ritual - the main event of the occasion. His counterpart and female schoolmate, Kurashina Hana, is a seasoned dancer of three years. As the festival draws closer, Yuuki becomes increasingly dissatisfied with his role, and eventually, he begins to perceive...?
Shy office worker x a Tsundere sweets-loving boss While desperately searching for a certain photo, she saw her boss, Hibiki Hasegawa making sweets!? She was so surprised because he has a terrible reputation in the company and in her surprise, she accidentally raised her voice and was then caught by him. [His true identity, which I thought was a demon boss, is actually a Tsundere!]
If the Science Club can frighten the Student Council President with their haunted house, he assured them of additional funding.
Ikezawa Sumire's 3 elder brothers, Asagi, Ai and Kon are so beautiful even friends get jealous! Sumire too loves Asagi and Ai, but for some reason she just can't like Kon. That reason is...!? Elder brother X3 + younger sister= HAPPY & SWEET!? Sumire and her elder brothers' full of happiness "at home" comedy.
From Esthétique: Sakura had lived with her grandma ever since her parents died in a car accident when she was three. When she turned fourteen, her grandma also passed away, leaving her alone. Just when she was about to give up hope having a family, out of nowhere, four guys claim to be her older half-brothers.
From Lililicious: A classic manga about girls at a private all-girls school. The storyline centers around the experiences of Nanako, a "normal" girl who is invited to join the prestigious school organization, the Sorority, and is resented by all the other students because she doesn't appear to be qualified. Other key characters are Nanako's two friends: Tomoko, her friend since childhood who is alienated by Nanako's decision to try to join the Sorority, and Mariko, a strange, obsessive girl who is invited to join the Sorority along with Nanako; her "older brother," Henmi, who she corresponds with by mail; and the "Three Magnificent Ones," all of whom are admired and quasi-worshipped by the rest of the student body: the head of the Sorority, Miya-sama, the haunted, pill-popping rebel, Saint Juste, and the star athlete with a mysterious disease who doesn't like the Sorority, Kaoru-no-kimi.