Narutaki-sou's Treasure. Kozue found the diary of his grandfather, who was once the owner of Narutakiso, in the warehouse where many old things were kept. There was an ancient map on it. According to the diary, it appears to be a treasure map that has been passed down from generation to generation in Narutakiso. The colorful Megumi and her friends start looking for a treasure, even though Takashi is not very trusting. However, probably because the map is old and full of bugs, it's hard to get to the treasure...