Oide yo! Mizuryuu Kei Land

In the near future, Mizuryu Kei travels to the deserts of Texas to try his luck as an oil explorer. Under the unforgiving heat, he eventually strikes black gold and establishes the Mizuryu Conglomerate. With infinite wealth at his disposal, Mizuryu Kei pursues his lifelong dream of building a theme park for sex. Long after his passing, Mizuryukei Land continues to be the bastion of sex in the world of manga, and the aspirations of the man himself have survived the test of time. The 1st Day follows five youths who visit the park on the same bus. First-time at the park, Yuta and Mai are a little shy at first. But caught in the magic of Mizuryukei Land, they eventually break out of their shell to indulge in their carnal desires for sex. Welcome to the Land of Dreams.

(Source: Irodori Comics)