Total Recommendations: 20
Both Yano in Bokura ga Ita and Arima in Kare Kano have a dark past. Although the female leads aren't similar at all, I think if you like one, you'll like the other.
Kotoko and Naoki's relationship really reminded me of Risa and Otani in Love*Com. I think if you like one, you'll like the other.
These two might not seem very similar at first glance, but both series have an adorable, very slow pure love story to them. If you enjoy the romance in Emma, I think you might like Kimi ni Todoke and vice versa.
I'm surprised no one has already recommended these 2 together. Both are by Mayu Shinjo (so smutty) and both deal with musicians, although Kaikan Phrase isn't focused on crossdressing. Kaikan Phrase also is more about celebrities where as Ai Ore is more about school students, but I think if you like one, you'll like the other.
These 2 really remind me of each other. Although Akira is post apocalyptic, and X is pre apocalypse, both have 1 special person who can destroy the world. They have a very similar atmosphere as well, and both have a prophet type character.
Both stories have humans who are involved with the spirit world and they are protected by spirits. If you enjoy one, you'll probably like the other, although Natsume is far more episodic than Kamisama.
Reverse harem, lots of bishes, although Miracle Train has a different girl each episode
Reverse harem shows based on otome games.
Both are centred around manga publishers, and have rookies out of their depth in a new situation, but in Love Recipe, there is a male BL mangaka and his new editor, rather than 2 new editors. I think if you enjoy one, you'll enjoy the other.
Although the plots aren't very much like each other (AD is not romantic), I think these 2 series are quite similar in tone, as both show tiny little developments in the characters each chapter. They're also both very heartwarming in their own way without being sickly sweet.
Both stories have poor girls going to elite schools and being bullied there but also finding love and acceptance.
Can't believe this hasn't been done. Both of the semes are arrogant romance novelists and both stories are extremely funny, though Junjou isn't quite as insane as Gravitation.
Both have "host club" type settings where a normal person is suddenly thrust into the situation and has to work there. They're both very funny too.
Both are very funny shounen-ai stories centred on crazy transport companies with very high standards of customer service.
Both protagonists have lost their parents and have to deal with life by themselves and are both set in different worlds than our own. They just really remind me of each other.
Same artist and a similar story
Both have cute guys who are (sorta) criminals and they're both very funny.
They're both about musicians and their relationships with both each other and music. Nodame's funnier though.
Similar sort of humour, and both have strong female leads. Both are very enjoyable too.