The scene when Yosano was invited to join the Detective Agency.
At eleven, Yosano joined the Great War because of her highly sought-after strong ability, and with that extraordinary healing power, drove the front-line troops to the depth of despair. The fear of being forced to fight until they die as long as Yosano is around led to rebels and even suicides. Yosano was hit hard by the curse of her own ability and shut her mind.
The one who opened that heart was the then-fifteen-year-old Ranpo.
It has been 11 years since then. Yosano and Ranpo, who became each other’s one and only colleague for a long time after that, still maintain that kind of closeness that is different from all the other members even now.
Also in Vol 8, there is a scene where Yosano said that she is “very grateful” for the invitation “even to this day.”