Nageki no Kenkou Yuuryouji

Hiroe Ogawa faced difficulties in the intimate sphere: she was unable to reach orgasm. Wanting to increase her sexual excitement, she decided to try a new sex toy.

Hiroe was secretly watched by her older sister Mayaka. Upon learning of this, Mayaka decided to join her sister. However, despite her best efforts, Mayaka was unable to make Hiroe orgasm. Then she suggested a new approach: she decided to hypnotize Hiroe in order to give her the desired sensations.

However, hypnosis also failed. The girls decided to continue the treatment and sought help first from a medium and then from a scientist.