Shingeki no Kyojin Season 2, Owari no Seraph Recommendations
Both are made by the same studio and share very similar traits.
-The survives of humanity are trapped inside a wall by an over powering force.
They both share the same characters; you can literally match the characters from both sides.
The plot is also the same; humanity is on a brink of extinction because of a source they know very little about and now humanity is fighting back.
If you liked Owari no Seraph you will love Shingeki no Kyojin!