Yu and Kurosaki-kun have started going out—on the condition that she “learns to obey him.” Brought down by her new boyfriend’s no-holds-barred training, Yu is, for once, doing as she’s told. When she stops clashing with Kurosaki-kun, she sees a new side of him, and just in time for their first Valentine’s Day to arrive. Yu is nervous, but come on, even crabby Kurosaki-kun has to accept chocolate from his girlfriend! If she can force her way through the crowds of the princes’ admirers to get it to him, anyway… Will Yu’s Valentine’s Day turn out to be sweet, or bitter? Plus, a new school year will be bringing changes to the dorm, too…

At long last, Yu can feel her relationship with Kurosaki-kun making some real progress after their Valentine’s Day connection—but she’s well aware that she and her bossy boyfriend are still far from on the same page, feelings-wise. Just as Yu psyches herself up to conclusively turn Kurosaki-kun’s head her way, the precarious pair is split up in the new school year’s class change! Even more worrying, the new transfer student—who happens to also be the prettiest girl in their grade year—has her sights set on Kurosaki-kun, and she’s willing to push much harder than the Black Prince’s usual fangirls. But Yu’s biggest surprise might come from Kurosaki-kun himself. Does the notorious Black Devil have a sweet side…?!

While Kurosaki-kun’s junior, Hino-kun, works from the shadows to isolate the now-popular prince from his friends and admirers, Yu remains blissfully unaware. The biggest thing on her mind is how far to take her relationship with her boyfriend! These days, the (former?) Black Devil seems sweeter and sweeter to her—and she doesn’t know how to handle it! She wants to connect on a deeper level, but when she and Kurosaki-kun end up in a fight instead, could it be that the unlikely couple is simply incompatible? But in the background, Hino-kun’s plans continue to escalate… Includes a bonus story starring Mina!

The secret is after their public kiss (doubling as an official relationship announcement!), the entire school finally knows Yu and Kurosaki-kun are dating. Yu is totally fired up to fend off any trouble that comes her way as a result, but her training is interrupted by Kurosaki-kun himself with an invitation to the summer festival. The date-like atmosphere prompts Yu to hope once again that Kurosaki-kun's feelings for her have changed from devilish dominance to real-life love. Before Yu can find out, though, she'll have to make it through the biggest predicament of her life...

In an accident at the summer festival, Yu lost her memories of high school, including her entire relationship with Kurosaki-kun. When Kurosaki-kune worriedly joins the amnesiac her on her summer visit with her parents anyway, Yu finds herself more and more curious... and her attempts to talk to him somehow culminate in a risqué encounter! Not one to be outdone, Shirakawa-kun whisks Yu away behind Kurosaki-kun's back. The two princes' showdown over Yu hurtles toward its finale. Will their friendship survive?

Yu's memories are back and her feelings for Kurosaki-kun are stronger than ever. Next thing she knows, a lingering hug turns into an invitation to bed from her boyfriend! But is Yu really ready to take their relationship to the next step? With Kurosaki-kun's devil of an older brother Sakura also meddling, and Yu's own desire to make her boyfriend happy, she knows she needs to make up her mind...

With exams safely behind them, Yu, Kurosaki-kun, and their friends are off on the class trip to Canada! On the plane, at Niagara Falls, a night out in Toronto... Kurosaki-kun's devilish teasing has gone global! When they meet his older brother Sakura's girlfriend, though, Yu can't help but notice how gentle her normally gruff boyfriend acts toward her. He might be having fun with this, but Yu's not about to let her man fall for any other woman!

"I love you." Yu is caught by surprise when Kurosaki-kun says those three magic words on a night out in Toronto. She's so happy she thinks she must be dreaming... Luckily, this is her new heavenly reality, one bound to make the rest of the class trip that much more exciting! But dating the Black Devil was never easy, and Yu's taste of bliss might be cut short by a new complication...

For Kurosaki-kun, Canada is more than just a fun class trip. The experience has inspired him not only to make some big plans for his future, but to waste no time setting those plans into motion. Yu, on the other hand, hasn't thought that far ahead. So when Kurosaki-kun asks Yu to study abroad with him, she's caught completely unprepared! That audaciousness is exactly what Yu loves about her boyfriend, and she doesn't want to be apart any more than he does. Still, it's a choice that will set the course of her own life. What will Yu ultimately decide?