Hiroto Komori lives a calm life with his younger brother Michito, who has autism; a little boy calling himself Lion shows up at their house.

Hiroto gets a message on Lion's phone directing him to a specific place; he tells Michito to look after Lion and sets out to find the location.

Hiroto believes he may have found out who Lion's father is; he takes Michito and Lion to go see Michito's art on display at the zoo.

After Lion suddenly comes down with a fever, a worried Hiroto takes him to the hospital but realizes he doesn't even know how old the boy is.

Kudo writes an article claiming that Aoi is still alive; a mysterious man tells Aoi her cover has been blown and helps her evade the police.

Hiroto reads a news article about Aoi and wonders why she would tell such a blatant lie; he learns the stunning truth about her and Lion.