Misaki Takahashi has little hope of getting into a university, so his older brother Takahiro's friend, Usami Akihiko, offers to tutor Misaki as a favor to Takahiro - for Usami is secretly in love with him. However, as time passes Misaki realizes that he has uncomfortable and budding feelings for Usami. Meanwhile, Hiroki is a man who can't get over an unrequited love with Usami in the past - and with the help of Nowaki, he may finally learn to love again. These couples and more experience the joys and sadness of love between men under the most unlikely conditions.
They are from the same author and studio so the animation is really similiar. Both of them is set in the same environment.
The characters from both animes have some sort of connection to each other and they are also similiar. Both features 3 couples and are shounen-ai (Boys Love).
If you liked one you'll like the other as well.
Fans of Sekai-ichi Hatsukoi 2 would do well to check out Junjou Romantica. The art styles are highly similar, and JjR replicates the same combination of reluctant uke + dominant seme with a slightly twisted sense of humor. If that's what you liked about Sekai-ichi, you'll find plenty more of it in JjR.
Misaki has made his way to attending a university, and continues to live with distinguished author Akihiko – a man who is persistent as ever in pursuing a relationship with Misaki. However, with Akihiko's editor insisting that Misaki keeps his distance to avoid scandals and Misaki’s stubbornness in full force, it’s difficult for the boy to admit his feelings to his benefactor. As if things couldn't be more complicated, the arrival of Haruhiko, Akihiko’s brother, throws yet another wrench in the gears. With Haruhiko now showering Misaki with gifts and Misaki's indecision on the rise, will Akihiko and Misaki finally see their relationship to flourish?
Both shows are pretty much the same but I enjoyed Junjou Romantica 2 much more than Sekai-ichi Hatsukoi 2. If you are interested in boys love these 2 titles are a perfect match. They are also Season 2's of their franchise.