Ikuto Touhohin just had a fight with his old man, one that led him to make a rash decision to run away from home. He boards a ship, deciding to take a vacation, but the ship is suddenly hit by a huge storm—one that sends Ikuto overboard! When he regains consciousness, he realizes he is still alive on some island. An isolated island. An isolated island with nothing but girls. Beautiful girls. Stranded on an island with only girls, no electricity, gas, radio, television, like he was back in the stone age. (Source: AniDB)

Adaptation of Takashi Noguchi's manga, which itself adapts Baku Yumemakura's supernatural romance novel. The original novel is about a 12th-century man named Minamoto no Yoshitsune (Kurou). Kurou flees into the mountains after losing to his brother Minamoto no Yoritomo, the first Shogun to rule all of Japan. History records that he committed suicide, but instead, Kurou meets a strange, beautiful woman named Kuromitsu in her mountain hermitage. Eventually, Kurou falls in love with Kuromitsu, but then realizes she conceals a dark secret. He learns that he is unable to die and continues to live for a thousand years as Japan evolves into a future society.

Suga Kimio finds himself hiding in the girls locker room, unable to move or escape the situation as the girls in his school crowd in. Although he originally had no ulterior motives, he found himself panicking as he heard the girls coming in and hid in a locker. Komine Nozomi, one of the shy girls in his class finds him, but surprisingly covers for him. Perplexed but glad, Kimio goes home. Later that night, he gets a text from Nozomi who happens to live across the way on the same floor of the complex they both live in. She blackmails him into agreeing to show each other's bodies when she texts him. Kimio has to abide by Nozomi's insane demands or risk ruining his school life so they both start their little peep show through each other's windows... (Source: MangaHelpers)

As with its prequel, Zoku Natsume Yuujinchou is about Takashi Natsume, a boy who has had the ability to see youkai since he was young, and his bodyguard youkai Madara, nicknamed Nyanko-sensei. Natsume attempts to return names written in his "Book of Friends" (which he inherited from his grandmother Reiko) to youkai in his village. Throughout these adventures, he meets some youkai that are friendly, some that want to steal the Book, and some that want to kill him, as Natsume learns about himself and his relationship with these mysterious beings along the way.