Episode 15 of Drifters shipped with the special version of the manga's sixth volume.

One summer vacation, Ruka meets two boys, "Umi" and "Sora," whose upbringing contains strange and wonderful secrets. Drawn to their beautiful swimming, almost more like flying, Ruka and the adults who know them are intertwined in a complex mesh... Meanwhile, an unexplained anomaly is occurring all over the world: fish are disappearing. Thus begins a marine adventure of boys and girls to captivate all the senses!

Gokuu Son and his friends are out camping when three mysterious enemies ambush them. After a quick fight, a fourth enemy named Cooler joins the fray. Seeking retribution for his younger brother Frieza after he was defeated, Cooler attacks Gokuu; however, the latter manages to escape with Gohan Son and goes into hiding. Unsatisfied and infuriated with the outcome, Cooler and his men begin the hunt to uncover Gokuu's location and kill him to carry out their plans of exacting revenge.

[Written by MAL Rewrite]

Basara Toujou has a hard life. He is the older step-brother to two demonic sisters, Mio and Maria Naruse, whom he protects from entitled demons looking to claim Mio's power for themselves. On top of that, rising political tension within the demon realm only makes his job more difficult. When a messenger arrives with summons for Mio to the demon realm, she and her friends go in spite of the danger. Now on the enemy's turf, Basara will have to grow stronger through erotic pleasure in order to do the impossible and protect everyone. [Written by MAL Rewrite]