Yasashiku Shite yo

When Subaru and Hayato were in the third grade, they became friends with the new boy who had moved in next door, Kengo. Now in high school, he is the only one who can tell the twins apart and one day, he catches Subaru in the act pretending to be Hayato to get a little "sneak peek" at what's to be on the quiz his class will have soon. Subaru is the mischievous type and thinks it's unfair how Kengo is only nice to the other twin, the ever calm and collected Hayato... but is that really the case?