Sterope-Sara
Celaeno-Lucia
Taygeta-Coco
Merope-Hanon
Maia-Noel
Electra-Karen
Alcyone-Rina
For the other characters, I'll use the kanji translations to Greek.
Once upon a time, there were seven sisters. Sterope, Celaeno, Taygeta, Merope, Maia, Electra, and Alcyone. They formed a star group called the Pleiades. One day, a demon named Kalos attacked the seven sisters and took Sterope as his own.
Seven years later, The other six stars are scattered all around Greece, assuming human form. Celaeno, despite being the brightest star as of now, doesn't know of her powers. But she also saved a boy named Thalassa from a sinking ship. Meanwhile, Alcyone and Maia teamed up but was quickly ambushed by a girl named Lili. Lili stole Maia but Alcyone ran away. Then there were only five sisters left. Celaeno met up with Merope. However, Merope was abandoned from the rest and therefore has no Idea the girl she was with was Celaeno. Meanwhile, Taygeta was looking for Sterope but she was quickly captured by Kalos. Four sisters left.
Celaeno saw that Thalassa was attacked by a woman named Izuru.(AN: I dont know the etymology of that name so I leaved it as is. I'll also leave Eriru's name as is. Also Maria and Hippo since those names are already Greek) Celaeno found out her power of her singing. She used it to attack Izuru away. Merope also learned of Celaeno's identity. They agreed to not tell anyone who is not a Pleiade that they are Pleiades. When Celaeno was attacked by a two faced girl named Eriru, Merope sang to help her. All they need to do now is to find the others and summon Astraeus.(AN: I literally used the goddess of the stars) Meanwhile, Alcyone met Thalassa. She mistaken him for Kalos. Also Merope found love in a guy named Thalassino Fengari, a lyre player. Celaeno felt jealous of Alcyone, thinking they're in love with each other. When she, Merope and Thalassa went to Thalassino Fengari's Concert. There was an instant attack by Lili. Luckily, Alcyone quickly came in and saved the day. She's the dimmest Pleiade but she can sing well. They also helped out a dolphin that was stranded by Izuru. The Pleiades can understand sea animals and they helped the dolphin find his mother. Then, the girls went to a shrine. The shrine was of Aphrodite. The Pleiades engraved the names of their lovers onto roses. Just then, an ice demon named Maria attacked them. Celaeno asked Thalassa to protect the roses. Although he didn't see who else's name is engraved on it, Thalassa saw Celaeno's rose. Celaeno, Merope and Alcyone attacked Maria and she disappeared.
A few days later, it was Celaeno's Coming of Age ceremony. Celaeno was supposed to have it a few years ago but because of Kalos's attack, it, along with Alcyone's Coming of Age ceremony, was postponed. Somehow, Thalassa followed them to Olympus. They were greeted by a boy named Hippo. Hera(AN: Not Taki-san, I'm using Hera) played a flute and Thalassa turned into a Prince. Just then, Kalos, Izuru, Eriru, Lili and Maria attacked them. A large water tornado separated Celaeno and Thalassa. Celaeno saw a figure that looked like Thalassa but was actually Kalos. Just then, Astraeus appeared and granted Celaeno love and power. Astraeus told Celaeno a story of how she sealed away Kalos a long time ago. Celaeno was able to defeat Kalos. Meanwhile, Thalassa was looking for Celaeno. He saw a star and recognised it as Celaeno. Celaeno returned Thalassa back to the mortal world.
And that's all I have time for. Let me know if you want more or if you want this in greek.