Books in the I'm the Hero, But the Demon Lord's Also Me series

As if learning that he may be both the hero and the demon lord wasn’t enough for Yuuma Tsugari to handle, beauties from another world keep popping up out of nowhere, throwing his normal life into chaos! The fight over him only gets worse when Princess Alfin’s little sister and one of the demon generals join the fray—and with an exhibitionist and a masochist now added to the mix, the number of erotic high jinks are sure to skyrocket as well. Yuuma’s life certainly isn’t ordinary anymore …In fact, he might be the (un)luckiest man alive!