While Pluto, as the Ruler of the Underworld, is obviously very sinister, seeing the Goddess of Spring sad appeals to his better side, and it shows that he really does want her to be happy, and allows her to return to her world above, but only as long as she promises to spend half of every year with him down in the Underworld.
Pluto scouts out the most beautiful woman on earth to be his queen and he decides that Persephone, the Goddess of Spring, is the perfect queen. He appears on earth in flames and abducts the beautiful goddess. He takes her down to his lower world and crowns her as his queen.
Meanwhile, on Earth, the world has turned cold and is experiencing an eternal winter without it's beautiful spring goddess. Down in the underworld, Persephone is depressed and longs for her world above. While Pluto may be sinister, he's not totally evil and her sorrow appeals to his better side.
He allows her to return as long as she spends six months out of the year with him. This short "explains" why we have the different seasons instead of an eternal spring.
Pluto and Hades are the same character on the show. It was evidenced when Hades demonstrate a unsuspected soft side: his love for Zelena (replacing Persephone), kidnapping her baby in the hope that she comes to him. Ironically, she was aspired into the same portal although he thinking that the witch was again in Oz. This love explain also why Hades had recreate the Underworld like similar to Storybrooke.
- "Pluto" is the Roman name for Hades, which is Greek.
- He has the same name as Mickey Mouse's pet dog.
- In terms of appearance and mannerisms, this version of Pluto is even more obviously devil-like than the already demonized Hades from Hercules, but in terms of his actions, which are less malevolent, he is a more accurate potrayal of the mythological character than Hades.
- In mythology, the story that inspired The Goddess of Spring was a part of the Greek's paganistic religion.