Akizuki Haruto, a police detective on childcare leave, finds himself solving cases using the hints he notices while raising his infant son, Ren, in this light mystery. Along with his wife Saki, Haruto is navigating the challenges of parenthood when he is unexpectedly taken hostage during a robbery. Despite the tense situation, Haruto uses his keen observation skills to gather clues and secretly calls his own police division for assistance. However, as he deals with the unfolding events, he must also attend to Ren's needs, including diaper changes and feeding times, adding a unique twist to his crime-solving endeavors. ~~ Adapted from the novel "Ikukyu Keiji" (育休刑事) by Nitadori Kei (似鳥鶏).