Futanari Shima: The Queen of Penis

Haruka, a futa girl, went on a tropical vacation with her lover Hitomi. It turns out that the Futanari World Cup is being held on the island, and she's forced to participate! To determine the strongest futanari girl on earth, all the most beautiful futa girls have gathered. The powerful Futanari Battle Tournament begins!
(Source: KTC, translated)