A mother-child disappearance case unfolds in Yamanashi Prefecture. Blood-stained clothing found along the riverside is confirmed to belong to Aoi Tachibana (Machiko Ono) after DNA testing. Aoi is Hiroto’s (Yuya Yagira) older sister, and questions arise: could her missing son, Shuto, and Lion (Tasuku Sato) be the same person?

Hiroto searches the news for information on the case and learns that Aoi’s husband, Shogo (Osamu Mukai), has been identified as an employee of Tachibana Urban Construction. With this lead, Hiroto becomes convinced that Shogo is Lion’s father and decides to confront him. Around the same time, reporters Kaede (Yuki Sakurai) and Amane (Takumi Ozaki) from Weekly Truth also track down Shogo.

Meanwhile, Hiroto, Michito (Ryota Bando), and Lion visit the “Morning Glory Zoo,” where a picture drawn by Michito is on display. After enjoying the zoo, the three head to the exhibit, only to find Michito’s coworker Onodera (Yusaku Mori), who is responsible for a live painting event, struggling with an accident.

Seeing this, Michito decides to take an unexpected course of action.