Karin is in the same grade as
Takaaki and the founder and only member of the "Mystery Club" before she manages to blackmail Takaaki into joining. Despite the name, the "Mystery Club" does not really read mystery novels or engage in real-life detective work, but is more a club for the occult, the supernatural, and unexplained. Most consider Karin an oddball, not only because of her interest in UFOs, but because of little things, such as her love for egg sandwiches and singing an odd nursery rhyme about eggs, as well.
[From
Wikipedia]