Mazome Soap de Aimashou!

Synopsis...

Marina Hishimori is the head of a school’s swimming club. She has a good pair of eyebrows, is a literate and martial artist, is adored by the younger students, and is an excellent coach. She is such a perfect girl that she despises the male members of the club who try to win by using sneaky tricks. However, one member of the club she adores contracts an incurable disease.
The only doctor who can treat the disease is, to her misfortune, the grandfather of one of the male members of the club, whom she hates. In exchange for the expensive treatment, Fujimori signs a “sexual friendship contract.” Will the noble girl be able to overcome the sexual friendship contract…?