If you liked
Kage no Jitsuryokusha ni Naritakute!
|
...then you might like
Tearmoon Teikoku Monogatari: Dantoudai kara Hajimaru, Hime no Tensei Gyakuten Story
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The Wisdom of the Shadows and the Wisdom of the Empire are basically the same thing but with a different premise.
If you liked
Shakugan no Shana
|
...then you might like
Nogizaka Haruka no Himitsu
|
They both involve romance, but I highly recommend watching Shana BEFORE watching Nogizaka since there are quite a few moments in Nogizaka that require having watched Shakugan no Shana (well, there's others as well but this is the most prominent).
If you liked
Angel Beats!
|
...then you might like
Mirai Nikki (TV)
|
They both share a similar characteristic of playing with your emotions, although Mirai Nikki has a much much stronger element of fear added in the mix. Both have strong plots and dark character backstories that become motives for their struggles. One could also argue that Mirai Nikki is a perversion of Angel Beats! since the participants are forced to fight each other to alleviate their live's sorrows instead of working together to overcome them.