Shadows Behind the Glass

Fifteen-year-old Dima is a good son and a model student. At school, he gets straight A's and steadfastly endures the mockery of his classmates, while at home, at his parents' request, he takes care of his younger sister. When she... begins to tell stories about toys coming to life at night and flying toothy fish, Dima takes it as regular nonsense. Until he starts to see them himself ― monsters that lurk in the yard, peeking through the windows. Thus, he gets into the Game, where anything is possible: even becoming a fearless warrior who kills monsters.
One day he meets a bird-girl named Ada in the Game. Dima vaguely remembers her face – she studied at his school and then went missing. It turns out that the Game is not a harmless illusion. It entangles the whole city... And the monsters are more than real.