Alright then, well for plot. Its bascially two things to choose. One is that one of the waiter comes in new to work in the cafe/restaurant place while the manager matched him with a beautiful waitress who seem to be cute and smart as unique from other waitresses. She has many personal problems but try not to show as she focused on helping the new waiter around the cafe/restaurant and telling him the rules and policy. But when he saw her that she is helpful yet beautiful, she couldn't resist on her as he started to become more closer to her by giving and taking as one night in a party, they went out as friends as they accidently kissed. This will be like long term roleplay.

As for second, they know each other but something happens to her at home as she couldn't help but be depressed till he make her day different. Mostly it's like she's a sicko person as hes the only one to help her.

And same for yuri. But you know, I am not sure if your doing Yuri (fxf) or (mxf)
They both will be the same except few difference and I played as a male once but really it failed because I messed the part and roles so I dont know now.

Hope it interests you :P