Conan, Heiji, and Kazuha attempt to head to an okonomiyaki restaurant before Conan has to leave Osaka. After getting past a talkative neighbor, a group of students challenging Heiji's deduction abilities, and crossing a busy street, the three run into a woman who asks them to take care of her baby, Kaoru. After the women disappears for a long period of time, Kazuha, while changing the baby's diaper, realizes that the baby wearing female clothing is actually a boy. Conan and Heiji, therefore, deduce that the woman kidnapped the infant. The woman soon returns and explains she found her missing husband, Hikaru, and had to chase him down. Hikaru explains he left their home after learning his Kaoru was not his. Conan and Heiji realize what's going on when the names Hikaru and Kaoru were characters from the book The Tale of Genji. Heiji explains that the Hikaru must have overheard his wife say that in the book, Kaoru is not Hikaru Genji's son. After sorting out the misunderstanding, the three continue on their trip until Conan receives a phone call from Ran telling him they have to leave thirty minutes earlier than expected as Sonoko was mistaken about the time of leaving and thus forces Conan to leave without eating.