Boogiepop wa Warawanai, Angel Beats! Recommendations
+ Both stories revolve around past events, how they affect individuals in the present, the ramifications of obsessing over past events, and letting go and moving on said past events.
+ Death is a driving factor many of the characters and the world (micro and/or macro level).
+ Finding/fulfilling purpose is something that is touched upon to varying degrees.
+ Both are set in worlds that have an underlying supernatural presence that continues to exist indefinitely, even after the story of the featured characters is completed.
- Angel Beats has a much lighter tone - literally and metaphorically - that eases viewers before and after