The series has always been a blend of wholesome and ecchi, it can be very lewd when it wants to be but also very sweet and wholesome at other times, sometimes both at once. I think the blend is balanced well, so even as a manga reader I personally don't think Iruru takes away or ruins the wholesomeness. I also think there's some interesting aspects to her character, plus the dynamic between these three is still there and wholesome as always.