The Other Worlds Association

Twenty-year-old Kisho Akita has his life turn upside down after a supernatural encounter with a vampire. Upon defeating it using critical thinking and common sense, he was tasked by a traveler from another world named Mai Harukami to help her stop the destruction of this world.

If only it was so simple.

Similar occurrences have been happening throughout many worlds. A godly dragon in the middle of a war between Cyber and Steam? A world where everything became invisible only showing their shadows? A generic fantasy world being taken over by an evil AI?

It won't be easy but if anyone can do it, it's not Kisho.

This series's multiple arcs may result in more genres to be explored than the ones stated. (One arc could be horror/thriller, the next could be harem/comedy)