From Fantasyshrine:

Ibuki lives in a university dorm where objects and people of different eras mysteriously pop out! One day, a stoical man, Haginuma, appeared in his bedroom and claimed to be his grandfather’s friend… who also had an unrequited love for his grandfather. Since Ibuki is a spitting image of his grandfather, will Haginuma devour him…?

Seven years ago, Atsushi locked his childhood friend, Kouichi, in a warehouse. After that, Kouichi developed a fear of dark places. Atsushi, who is tormented everyday with the knowledge of his crime, is pushed down by Kouichi, who says, "if you're sorry, let's do it."

From Ikemen Scans:

After his parents go overseas for a few months to work, Kouta, a college student, gets to live in the family house again with his brother Tetsurou, who came back from Tokyo to keep him company. Kouta hasn’t seen his big brother for six years, and doesn’t really get along with him. The situation soon gets awkward when Kouta realizes he doesn’t know anything about his brother... And it gets worse when he becomes aware that the antipathy he felt towards him, might be more ambiguous than he previously thought...

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...

From Eggy Scanlations:

Even though you are a playboy, kissing so clumsily breaks the rules!

Uncommitted playboy teacher Kurosawa does not refuse anyone who comes to him. His serious student Mamoru hates playboys and is appalled by his teacher behavior. After accidentally witnessing Kurosawa and his girlfriend fighting, Mamoru instinctively scolds him. But Kurosawa suddenly says I like guys like you,and gently hugs him. Playboy teacher x earnest student love!

In the other stories, the love between an adult and high school student: Meeting at the sea.