SM, sadist ML x masochist FL (she's only masochistic with him. Otherwise, she's a COMPLETE sadist. I'd say she's a switch, but it's kinda complicated since it's only with her boyfriend that she becomes masochistic. I'd say that'd make her 99% sadistic and maybe 1% masochistic. Although, with him, she's COMPLETELY masochistic. It's not just that she takes on that "role", rather, her entire personality changes. Like a switch is flicked.)
Switch FL and ML. Most of the time (like 80% maybe), Yuri is submissive, but she sometimes loves and really gets off on dominating her boyfriend. Oya is usually a Dom, but sometimes he loves being dominated by his girlfriend. Hence, I'd say they're both switches. They're not sadistic or masochistic, though.
Tentacles
Sextoy, light bondage, spanking
Sadistic Secrets and Masochistic Mysteries