Once upon a time, there were two rival kingdoms that did not get along. Every day, they argued over insignificant matters. When a dispute over removing dog waste ultimately turned into a war, God swiftly intervened and directed the two nation's leaders to exchange the most beautiful girl and the most intelligent young man for bride and bridegroom, respectively. Saara, the princess of country A, meets the prince of country B, Naranbayar. As they pretend to be a married couple to protect the peace between the countries, they find themselves gradually falling in love.

Uta, who works and lives in a hotel on Uranus, has always thought that she is different from other people. Whenever she has free time, she sits in front of her computer making things she likes and enjoys herself alone, or goes to cafes alone. One day, she receives a "Future Ticket" - the key to a new life. Despite this, Uta continues to live her life as she always has. However, as the "Star Festival", a festival to commemorate the closest point between Uranus and Neptune, approaches, she meets Paula, a popular influencer from Neptune whom she admires. After becoming close to her, Uta makes a major decision about her life.

Kanenone Gakuen is an all-male boarding school located in the countryside of Japan. Although an all-male school is nothing new, life can become quite difficult when there are no female students for miles around. In order to help the psychological health of everyone involved, the school board has decided to try and merge with the nearest all-girl boarding school in order to become co-ed. The boys of Kanenone are more than thrilled at the prospect, and the girls are curious as to how interesting school life might become if there were more boys around. Before any serious decisions are made, the girls have been invited to stay at Kanenone for one month as a test. Green Green follows Yuusuke Takazaki and his naughty room mates called the Baka (Idiot) Trio, and their ability to talk to the girls without making complete fools of themselves. But as soon as the school bus with the girls arrives, things become weird, hormonal, and hysterical. In particular, a girl named Midori Chitose leaps off the bus and immediately embraces a very confused Yuusuke. Is he a natural ladies' man, or do the two of them have a shared history that he is not aware of?

After his mother passes away, Taro Hanaukyo is invited to his grandfather's home. There, he meets a beautiful maid named Mariel and finds out that his grandfather has retired to a remote island and has given him ownership of his estate. Taro also discovers that not only is the estate a colossal mansion, it has hundreds of gorgeous maids ready to serve him 24 hours a day, seven days a week.