Description:
One day, while we were living happily with Natsu, a group of yakuza suddenly appeared before us. They said that Natsu had run away despite being kept by the yakuza as collateral for a debt. As we tried to take Natsu and leave, we ended up getting kidnapped after a scuffle.
And the Yakuza imprisoned us, saying with a lewd smile that if Natsu could endure a week of forced sex training, they would release both of us...