phenomen a book

Synopsis: Kenji Arata, a 15-year-old boy living in the city of Karinome, thought the hardest part of adolescence was passing his exams and confessing his feelings to his classmate Airi. However, when he begins to notice strange beings called "Void echoes" causing chaos in the city, the teenager and his friends must become "Echo-Chasers" to keep their home safe.