Taka (technically Tamahome) and Miaka are now happily married and only six months before their new family would be born, but an obsessed girl named Mayo would do anything to make Taka hers. She enters the world of the Four Gods, determined to win Taka's heart and be the new priestess.

A squid-like creature, known as a Happian, leaves his home planet with the desire to spread happiness across the universe. He lands on Earth, but quickly finds himself in danger of captivity by its inhabitants. Fortunately, he is found by an unsmiling little girl named Shizuka Kuze, who feeds him and names him Takopii. Feeling indebted, Takopii decides to do everything in his power to bring a smile to her face. The task is easier said than done, however. Shizuka is bullied by her classmates, she does not have a father, and her mother is never home—though the gravity of these issues flies over the naive Takopii's head. Even so, Shizuka does have one source of happiness: her dog Chappy. The connection Shizuka and Chappy share only increases Takopii's desire to make the girl smile. While Takopii's attempts to lift Shizuka's spirits lead to unintended consequences, he is determined to take things into his own tentacles, test his understanding of human beings, and achieve his goal of spreading happiness.

In this adaptation of a manga by Fumi Shibama, itself a retelling of a 1972 manga by Kazuo Kamimura (the original Age of Cohabitation whose existence is implied by the "new" in this title), Honda has been living with Eri for two years and debates whether or not he should ask her to marry him.

1887, at a remote, elite boarding school in France: Serge Battour returns after his graduation, and remembers the days of his youth... 1880, at the same school: Son of a viscount and a Roma prostitute (both deceased), Serge is intelligent, sweet, talented, and alienated by his family due to his heritage. Upon being sent to his new school, he rooms with Gilbert Cocteau, a gorgeous loner of a boy who sells his body for reasons unknown. Serge's attempts to reach out to Gilbert fail spectacularly, and yet there is something in both of them that attracts them to each other.