I understand, since Akira grew up in a village that is mainly comprised of women, it is natural that he would end up liking and doing girlish activities and things due to the culture and environment he lived in. Also, since no one here talked about it, the tainted part might be...... The fact...
Dam, Thistle is pretty badass to turn a demonic genie's power against him, since we know that it's usually the demon that turn against its user after they gain enough power from desire
100 years vs 1000+ years of history, from all over the world, any place, any time. Also, it seemed like only just recently that they enrolled themselves to a school so most likely how they pick where they go is find information (from books and sort) for any interesting place in history and go...