Bunbetsu To Takan分別と多感; Funbetsu to Takan; Sense & Sensiblity; Sense and Sensibility

From Jshoujo: Aya has a great boyfriend Kento who treasures her a lot. But she is also attracted to Kento's older brother, who has a twisted personality. How come she can't stay away from him and she goes so far to cheat on her boyfriend? Will Aya's sense prevails over her sensibility? Includes two side stories.