不倫相手の息子・三宅渉(野村康太)が通う塾で勤務を始めたみのり(松本まりか)。正体を隠しながら渉の父親を調べるため距離を縮めていく。渉の父親は夫・勇大(竹財輝之助)なのか…。親身に相談に乗ってくれるみのりに少しずつ心を開いていく渉は、自身の幼少期の話をする。疑惑が深まる中、母親の理子(野波麻帆)が倒れたと一報が。病院へ向かう渉の後を密かに追うみのり。病室の理子と渉の元に、勇大が遅れて到着する…。
Minori (Matsumoto Marika) begins working at the cram school attended by Miyake Wataru (Nomura Kota), the son of her affair partner. While concealing her true identity, she closes the gap in order to investigate Wataru's father. Is Wataru's father her husband, Yudai (Takezai Terunosuke)? Wataru slowly opens up to Minori, who kindly gives him advice, and tells him stories of his childhood. As his suspicions deepen, he receives news that his mother, Riko (Nonami Maho), has collapsed. Minori secretly follows Wataru as he heads to the hospital. Yudai arrives late to join Riko and Wataru in their hospital room.
