Nagasarete Airantō : ながされて藍蘭島 - "Tobidashite, Airantō" (飛び出して、藍蘭島) Episode 26

Ikuto and Suzu arrive on a small nearby island to the cave and gate where the Sea Dragon God sleeps, in which the dragon can send Ikuto off the island and to find his sister Misaki. After meeting her and learning she's safely living on a male version of Airantou, he makes the decision to go back to the island much to her dismay. Upon his return, he is welcomed by all the girls on the island and Obaba informs Ikuto that he will have to go through another tournament that would decide which of the girls on the island would be his bride. The story ends with Ikuto being chased by all of the girls on the island.