Short and diabetes-inducingly-sweet couple manga.

From Senpai Scans:

Let us search for fellow youthful club members for our mysterious club activities!
Because of her father's adventures, Miku is entering school three months late. As such, she's petrified of being excluded and not having friends. He, the school special's extracurricular "finder", gave Miku an opportunity to make friends. And thus, somehow, Miku managed to join a club...

1) Shuu7 (7 Days of Week)
Kae likes Seto from her summer job, but when she's about to confess she accidentally sees Seto confessing to another woman who turns out to be married. After Kae sees Seto turned down and heart-broken she bids him farewell...and meets again in school...will Kae finally confess to Seto...? will Seto whose field of vision is narrow recognize Kae...?

2) LoveChuu (In Love)
Saya is an energetic girl who loves high places, but is always teased by Ryou Natsume. Although Saya considers him as a "Black Devil King" she loves him all the same, but is afraid to confess in fear of being ridiculed and teased by him...

3) Koi no Kajitsu (Fruit of Love)
Yuzuhara had to quit the track and field team due to an injury and is down because of that...then one day Tooda Shuuhei pops in at the window where she sits and asks her to date him...although shocked Yuzuhara agrees him to see at her window seat for a month until her seat changes...but on the last day before her seat changes Shuuhei doesn't turn up...

4) Sweet Little Winter
Kaoru has liked Nayuki since childhood. Nayuki has only thought of him as a little kid whom she takes care of, but when she found out that Kaoru was going to go to another high school, Nayuki was surprised when she realized she didn't want Kaoru to go...

The series is composed of four protagonists.

Nori: An energetic, upbeat girl who was heartbroken sometime ago due to her childhood friend. Now she is headed to meet Haruna, the lonely kid she always played with back then, but to her big surprised grew up into a hunk.

Kyou: The school's prince. From a distinguished family: he is handsome, smart, athletic and rich. He has never struggled for anything in his life, be it money or women. Haruna's sudden return throws him off momentum.

Saeka: She, Nori and Kyou are childhood friends. She is mature, composed and understands the two quite well. Although beautiful, she has been in love with her teacher since middle school and therefore never gone out with anyone. Will her feelings be answered or will she find an unexpected love around the corner!?

Haruna: The boy who comes back after having been away for many years. His reason for returning is unknown. The guy who’s clouded with mystery shows interest in Nori. Does he really like her or is there something else behind it...

Summary: Nori Sakurada is riding her bike one day, when she meets up with a boy she used to know when she was little. He has grown, but doesn't look very happy...

Also contains a side story called Himitsu no
H-kun in vol.1:
The well-known and popular Hakozaki-kun is the dream of every girl in Miwako’s school. However, he's hiding a secret! One day while walking down the street, Miwako notices him secretly taking photos of elementary schoolers!! Could it be that the famous Hakozaki-kun is actually… a… a pervert?!