Are there any doujins (or mangas) that contain sex, implied or explicit, but aren't [b] that have long sex scenes every chapter?

In other words, I'm asking for a story, and more than standalone chapters or 3-4 chapter arcs.

¯_(ツ)_/¯

Sorry, i don't really understand what you seek. You search for long mangas with sex, and not only short 1-2 chapter storys?

Try some works from these authors :
Fuuga the diferent books has conections in them,
Manabe Jouji long storys like Ring x Mama, Tail Chaser
Sanbun Kyouden extreme rape, mind break and other things, not for the weak
Chuuka Naruto extreme mind break, rape, and old man but strangly addictive
Takasugi Kou heavily censored
Tsukino Jogi really great storys like ♭37°C, After School (TSUKINO Jogi),

but there are many more to read like
Take on Me, Sakura Democracy!, Blue eyes, Brandish etc

What type do you want to read?

Something Border line H like Ore Tama Perhaps?

or somethin with lot of sex AND a story?