From JShoujo Scans: Hana is a 16-year-old girl who's a bit of a tomboy. She gets dumped by her boyfriend when she moves to Sapporo after her parent's divorce. On her first night there, she comes across a young guy who is seemingly too ill to walk. He ends up collapsing on her and is quickly rushed to the hospital. As it turns out, he's her next door neighbor, Shindou Hiroto. The next day, when she goes to her new school for the first time, she finds out that he's actually a teacher and that he's the teacher of her class! With his out-going personality and friendly demeanor, he gets along with everyone, but she notices there's something a little different going on between him and Nishiwaki, a classmate of hers whom the others write off as a "cold-hearted beauty." Hana always runs into him on her way to school, and as she gets to know him more, she finds herself falling for him! Things get even more messy when her boyfriend who broke up with her comes to Sapporo saying that he wants to give their relationship another shot!

From ShoujoMagic:
The two high school girls, Hanazono Mito and Tatsuda Seshiru, have been friends since kindergarten. But while Seshiru is an honour role student, Mito is constantly breaking school rules.

One day, Mito helps Seshiru evade the advances of the arrogant Ran, a rich boy and model who mistakes Mito's interference for jealousy (because of course every woman wants Ran for herself! Yeah, right). This lands Mito in hot water with Ran's fangirls, who later gang up to kick her ass! A new transfer student with wild hair is the one who saves her, but he won't tell Mito his name...!?

From Girls' Generation Scanlations:

1-2) Ouji no Kikan
Satake Kou attended the wedding of his sister where he was reunited with his cousin, Fumihiro, who used to be a very dumb fat guy, then transformed into a charismatic prince! Kou became undeniably self-conscious about this while not being aware of Fumihiro's high regards towards him since they were little. Fumihiro's admiration has turned into something complex. How would Kou respond to Fumihiro's feelings?

3-6) Metamorphosis
Adachi has been friends with Ritsu since they were children. Suddenly, Ritsu starts changing and acting like Adachi has never seen him act before... and the reason for that change seems to be Ritsu's new senpai, a troublesome guy. Adachi slowly realizes that he feels more than just friendship towards Ritsu... but it's too late.

7-9) By His Side

10) Ouji no Kikan Extra

A one-shot collab between Hatta Ayuko (Ookami Shoujo to Kuro Ouji) and Mizuno Minami (Nijiro Days). Sata Kyouya is the school’s guidance counselor and he has to deal with an odd group of students.

From Chibi Manga:

Kaji, Yuzuha's unrequited love, is a good friend of her twin brother Suguru. He's the same age but goes to a different school and since elementary school, he's been going in and out of Yuzuha's home. She's been in love with him all this time, but can't make a serious face when around Kaji. Now they both change to the same high school and there's the chance to decrease the distance between Kaji and her...?!

This collection, titled simply Short Program, collected stories by Adachi published between 1985 and now.

Volume 1 (from Shougakukan):
1. Kinkyou "Recent Times" [1987]
2. Kousaten mae (Before the junction) "The Intersection" [1986]
3. Shooto Puroguramu "Short Program" [1987]
4. Teiku ofu (Take off) [1988]
5. Chenji (Change) [1985]
6. Purasu 1 (Plus one) [1986]
7. Murasaki (1985)
8. Nani ga nandaka (What is what?) Part 1 [1985]
9. Nani ga nandaka (What is what?) Part 2

Volume 1 (from Viz)
Story 1 - Change
Story 2 - Take Off
Story 3 - Short Program
Story 4 - What's Going On!? (Part 1)
Story 5 - What's Going On!? (Part 2)
Story 6 - At the Intersection
Story 7 - The Current State of Affairs
Story 8 - Plus 1
Story 9 - Purple

Volume 2:
Story 1 - Before Spring Comes
Petit Comic April 1992
Story 2 - Subject - Wakaba
Weekly Young Sunday January 1995
Story 3 - A Stop on the Way
Shōnen Sunday September 1994
Story 4 - 5X4P
Big Comic Superior July 1992 - September 1992
Story 5 - 4 on the Richter Scale
Shōnen Sunday July 1988
Story 6 - Aim At the Ace
Shōgaku Shinen Sei June 1986
Story 7 - Spring Call
Shōnen Sunday April 1993
Story 8 - Spring Passes
Big Comic Spirits May 1993
Story 9 - The Road Home
Young Sunday October 1989 - November 1989
Story 10 - Sayonara Game
Big Comic 1991 Summer Special

Volume 3:
Story 1 - Clogs and Diamond
Story 2 - Where the Wind Blows
Story 3 - Angel's Hammer
Story 4 - Memory Off (part1)
Story 5 - Memory Off (part2)
Story 6 - White Summer / Shiroi Natsu
Story 7 - Square Ocean
Story 8 - Idol A (part 1)
Story 9 - Idol A (part 2)
Story 10 - Idol A (part 3)
Story 11 - Running God
Story 12 - Short Mail

Volume 4: Girl's type
1. Short story of a parasite (part 1)
2. Short story of a parasite (part 2)
3. Harsh life of a parasite
4. Love confession
5. Season
6. Two champions
7. Capricious Punch / Kimagure Punch

Two high school girls are complete enemies, and they both are in their own gangs. They fight each other all the time, and to get even with the other, one girl tries to kidnap the other's boyfriend. But the information her right-hand girl gives her is wrong, and they kidnap some really good-looking guy who is NOT the boyfriend of the other girl. You know what happens. They fall in love.

Side story: Photogenic
Photogenic centers around the girl in question, who has gone to cram school every day of her school life, finds a photo of an amazingly cute guy, and imagines what it would be like to be his girlfriend, instead of being one of the smartest girls in Korea.

Collection of oneshots:

1. Prologue

2. Suki no Kimochi

3. Suki na Hito no Suki na Hito

4-5. Kimi no Kanaderu Hikari (The Light that You Create)
There’s a rumour going round Yuki’s school about a ghost who inhabits the old music room. One day, while playing the piano in the music room, Yuki is approached by that ghost…
- The Zero Alliance

6. Neko to Shakushi to

7. Tama ni Onegai!
A short story about a boy who copes with one of his friend's strange fetishes...
- BlindingLight

8. Suki to Gomen ne

9. Are kara, Kore kara

Compilation of short stories:

1) Samurai Darling
Amiko saw a boy dressed like a samurai at a school festival. What will she do?

2) Toumei Shoujo (Lucid Girl)
Yuki rejects a present from his childhood friend Risa, but something happens and he sees things from a different point of view.

3) Some Kind of Childhood
Rika doesn't understand the point of kissing. Will she change her mind?

Kiyora is a bored student at St. Joanna all-girls school. Using one of the books her father sent to her, she unleashes a demon, and then begins to investigate the disappearance stray cats from the school's campus in the hopes of unmasking the virtuous priest, Father Shion.

One shot by the new Mangaka released in the 11th issue of Comic Alive 2013.

Zion, a girl that is always taken advantage of by her friends because she is so shy and timid, is approached by two people who asks her strange questions about whether she believes in Confucianist moral doctrine and in the end she is bowing and performing sacrificial rites to ancestral gods. It’s shocking enough that the daughter of a pastor is possessed by a ghost, but what’s more shocking is that this ghost is a young oppa who sports a fashion that surpasses most of the outstanding looks of bachelors and rockers! From this day on, Zion’s life changes forever. From a shy and unsuspecting high school student, she turns into an exorcist.

From Royal Alliance:

Inori is an honor student in a witches' school. In order to pass her final exam to graduate, she has to make a "love potion." In order to make that "love potion," Inori lives in the same house with Aoi, in hopes to get him to fall in love with her (required for the "love potion.") The only problem is they don't get along at all! So how will Inori get Aoi to love her when he's always picking on her?!

Houjou Hinaki is a young girl who has in her possesion a ring, a gift from her father. Anyway, this ring is not an usual one. When she kisses it, a young noble man named Sae appears in front of her and grants all her wishes. However, Sae is trapped in the ring and can't tolerate much time outside and together with Hinaki and her freaky schoolmate Yume-senpai, tries to find out a way of how he can escape from the ring's prison.

A collection of 6 stories.

[STORY 01]
Suki Ja Nai (I Don't Love You)
"If you always say 'I love you,' you'll find happiness." Thanks to grandmother's good luck charm, Rio is a very happy and bright high school girl, well-liked by everyone because she tells everyone that she loves them. ...Except for a boy in her class named Kaito. For some reason, he's different from everyone else. He makes Rio nervous and gets her heart pounding, and she can't communicate an "I love you" to him. Just what's going on!?

[STORY 02]
Koi No Mukou (Beyond Love)
Stories 2 and 6 are continuations of the first story.

[STORY 03]
Kiss No Jouken (The Terms of a Kiss)

[STORY 04]
Touched by Love

[STORY 05]
Surprise Attack

[STORY 06]
Happy

From Chibi Manga & Intercross:

Can a cute but misunderstood girl ever get a good looking and super popular boy?! Well, like yeah! That’s why Christmas miracles exist!

-
Kotoko has been dumped the day she decided to introduce her boyfriend to her friends. Desperate, she fall down face to face with one of her classmates: tall and dark, as was her boyfriend. She decides to use him for to not lose face. But is it really a good idea ...?

NOTE: Oneshot "Futei de Furachina Ani desu ga. R ~Ayumu, Kaikin~" isn´t scanlated.

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.

Included in this work are the following spinoffs:

• Himegoto +
Hime's younger brother Kaguya joins the public morals committee because he wants to save Hime from the clutches of the student council vice president.

• From Comic Rex and Febri

Two high-school boys run into each other, and find that they've swapped bodies.

From Kokoro no Oasis:

Lina is an honor student on a mission to be perfect, and all's going well... until the free-spirited Prince Gigi transfers into her class.

1) Goshujinsama ni Kiwotsukete
When his twin sister breaks her leg, she forces Tsuda to substitute her at her secret job as "Ruu" a waitress in a maid cafe. Of course, on his first day classmate Kaname shows up! But they're not close and Kaname has a hard time remembering people's faces...

2) The Romance Hidden in the Student Council Room
Over-achiever Kamida is used to manipulating people to suit his own ends, so gentle Kijima doesn't stand a chance. But Kamida is pretty stupid, and Kijima is unexpectedly stubborn. Can they get their feelings through to each other?

3) My Favorite Lunch
Company president Watanabe Kouichi is a bottomless pit and junior secretary Aibo Shuu is given the responsibility of keeping him fed. But the president is young and handsome and is being pushed to marry soon, and with a wife at home to make bentos, will Shuu still have a place next to the man he admires?

4) The Witch in the Health Room
Atsurou thought life at an all boys school would be boring, but when your cousin is the school nurse and a beautiful young crossdresser, it makes things more interesting, unfortunately.

5-6) Family Pop
Hopeless college student Minoru doesn't know what to do when he's suddenly stuck babysitting for his cousin's daughter, sparkly classmate Ogura offers to help is a godsend. But family life quickly becomes very comfortable for the boys...