 If you liked
Durarara!!
|
 ...then you might like
Kuzu no Honkai
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Multiple love triangles in both series. (Ex: Mugi, Hanabi, Sanae in Kuzu no Honkai and Mika, Seiji, Namie in DRRR !!)
Many romances or twisted loves between the characters. (Eg Akane of Kuzu no Honkai or Haruna of DRRR !!)
These series are very focused on the psychology and the development of the characters.