Second story (chapter 5 and an extra in chapter 6): Very cute, albeit a bit short. About a city boy who moves to the countryside and befriends another guy who's similar in age as him. The first (main) story in this one is a bit of a heavy read (trigger warning for sexual assault), so I'd recommend skipping the first story if that's not something that you think you'd want to read.
A story about two college friends. One guy (straight) has terrible luck with women and is constantly getting dumped. Every time he gets dumped, he goes over to his friend's place to seek comfort from that friend (gay). One thing leads to another...
Two guys who have been lifelong rivals since high school are now working at the same company. They can't help but turn everything into a competition, and that applies to their love lives as well. Naturally, they make the perfectly reasonable decision to sleep with each other to see who's better at sex (it's just a competition bro, there's nothing more to it...) and now the race is on to see who can get the other to fall in love first. Whoever falls first is the loser!
Childhood friends get caught up in the moment and begin masturbating together and jerking each other off, which turns into a regular occurrence. Feelings develop. Also has a couple of sequels (one set during their college days that's untranslated and another story about them as adults that can be found on this website.) Very cute story!
First story (chapters 1-4 and an extra in chapter 7.5): Two childhood friends, both virgins, practice kissing each other to gain more experience for their future girlfriends. Anyway, they end up having sex... but wait, there's a twist!
Chapters 1-4: Two high school classmates begin living under the same roof due to, uh, circumstances. An attempt to watch porn together ends up with them jerking each other off instead and then some. The characters shown on the cover are a side couple (chapters 5-6.)
A high school student discovers the wonders of anal masturbation and enlists the help of a fellow classmate to improve his prostate "development." A surprisingly wholesome and cute story with great art!
A guy gets dumped by his girlfriend because he's more interested in sex than being in an actual relationship. He then gets involved in a "friends with benefits" situation with another guy and real feelings start to develop...
Who needs a *boyfriend when you've got your homies?
Hitori to Hitori no 3650nichi