Overview: Seiya is asked by Chief Yamaguchi, who has come to “Holmes Agency”, to take care of Momo for a while, as she is overworked. Seiya and Ryosuke hoped that Momo could cook for Kyoko, who is on a business trip, but all she could think about was the case she is currently investigating. The case was a serial arson case. Seiya, who accompanied Momo to investigate the crime scene in defiance of Yamaguchi's orders, finds curry in a charred cauldron in the kitchen, which renews his sorrow. Seiya also visited another house where the crime scene took place, and found testimony that the fire broke out while everyone was eating curry together. Soon after, a boy named Kindaichi, who was with Seiya, met his classmate Saya Endo. Saya lives near the crime scene with her mother because her father has been transferred to work alone. Her mother is also busy with work, so she is often home alone.