This one is kinda old. But basically it's a modern setting where everyone is in a friend group . Sesshomaru and Kagine are close friends who met after Inuyasha abandoned her at his party for Kikyo and years later are secretly dating( but really on inuyasha doesn't know) Kagura is dating both Ginta and Hakkuk and finally notices that Kagome and Sesshomaru and more than friends when they're all at a bar one night. Also Kagome gives Sesshomaru a tattoo to Mark him as hers so his father will stop arranging a marriage for Sesshomaru. Really hope someone can help me. Thanks in advance.

It sounds like Progression by Sidhe. Which is very much MA.