Updated to include the sequel manga Amaenaideyo!! MS.
Amaenaideyo!! and Amaenaideyo!! MS manga (complete)
The second manga is quite a bit more ecchi than the first, with the main difference being that the girls themselves seem to power up from perversion instead of the protagonist as the story moves along. Because of this, clothes come off more readily than ever in the later tankobons.
It actually kind of reminded me of To Love-Ru Darkness in the sense that the girls are almost constantly naked while the manga remained in a shounen-comedy setting.