The teacher Miyagi was in love with in high school, and continued to love until he met Shinobu. She died because of an incurable illness when Miyagi was in his university years, therefore we can see her only through Miyagi&#039;s memories.

Three very different couples caught up in a storm of pure romance! 
Romantica: Misaki is struggling to prepare for his college entrance exams, so his brother arranges for a private tutor. But Misaki's nightmare is just beginning when his tutor, Usami, comes on to him! How will Misaki ever manage to pass his exam? And why does he feel so mysteriously drawn to Usami? 
Egoist: Just when Kamijou's life is at its lowest, he has a chance meeting with a man who never lets anything hold him back: Nowaki. His name means "typhoon," and he's about to take Kamijou on a whirlwind ride that will turn everything upside-down. 
Terrorist: Miyagi always seems to shrug off the cares of the world with a joke and a smile, but even he has problems, although he doesn't let them show. Foremost is Shinobu, a relentless young man who's adamant that they're destined to be together. 
(Source: RightStuf)

The second part of Junjou Romantica continuing the story.

Sensei