The Underworld Is Wide Open and My Wife Comes Uninvited

When I was born, the Ghost Festival was approaching and the Tengu eclipsed the sun. It is in response to a sign that is kept secret among the people: on the fourteenth day of the seventh month, the king of hell recruits a son-in-law; on the fifteenth day of the next year, he welcomes him to the underworld. After that day, I had a wife... The most common thing she says is: "You just need to keep fit, I will be invincible in the world."