Ep 10. The Butterfly Vanished in November, Part 1

Sakurako and Shoutarou are out on a field trip, examining butterflies for Sakurako's research. While they are taking a break, they come across a butterfly collector's store and decide to check it out. They meet the owner, Konno-san, who is an elderly man with a love for butterflies. He shows them his impressive collection and even gives them a rare butterfly as a gift.

Later, Sakurako receives a call from Konno-san's granddaughter, Hiyori, asking for her help. Konno-san has gone missing and Hiyori is worried about him. Sakurako and Shoutarou head to the man's home and start investigating. They find a mysterious note that leads them to believe that Konno-san may have been in trouble with some dangerous people.

As they continue to search for him, Sakurako and Shoutarou uncover a dark past involving a previous butterfly collector who had been involved in illegal wildlife trading. They realize that Konno-san may have stumbled upon some information about this collector and may have been targeted because of it.

The episode ends on a cliffhanger, as Sakurako and Shoutarou are attacked by an unknown assailant while they are investigating Konno-san's disappearance.