Hero Syndrome, Vol. 2 (light novel) — Rei Ayatsuki

Two months have passed since the fight against the Goddess in Akihabara. The members of Charon are in training, still attempting to recover, when a young woman named Haru Takanashi is sent to join their ranks. Haru has clearly been dispatched by the higher-ups to “observe” Charon, but Kaguya remembers her own early days in the unit and decides to extend a friendly hand. Unfortunately, it looks like this new girl is going to be an even tougher nut to crack than Azuma was! Regardless of what Haru says, Kaguya knows that saving people is the right thing to do. More determined than ever, Kaguya sets her sights on the furthest reaches of salvation, where she finds hope, jealousy, cynicism…and betrayal.