The Sun is at the center of the solar system and is the closest star to Earth. Various celestial bodies, including Earth, revolve around it. He absolutely hates it when his planets stray from the orbits he has set. He displays a fairly psychopathic side, and while his way of expressing himself is very bizarre, he cherishes all the celestial bodies formed by him. He is kind yet bizarre.

Mercury is the smallest planet in the solar system and the closest to the Sun. Male. The Sun considers him a best friend, but from Mercury's perspective, the Sun is a crazy star that constantly fires flares near him, making him the person Mercury wants to avoid most. He is timid.

The fourth planet of the solar system. Male. Moons: Phobos, Deimos. He is easygoing and a tsundere.

The second planet of the solar system. Nickname: Goddess of Love. Male. He is Earth's neighboring rocky planet. To put it nicely, he is easygoing and tough; to put it bluntly, he has the personality of a thug. He hates pretty or feminine things intensely.

Earth is the third planet from the Sun and the only planet where living things reside. Male. Moon: The Moon. He is playful and bright.

Male. One of Earth's satellites. He has another persona on his far side called the 'Dark Side.' The front side is kind, but the back side is blunt and psychopathic.

The largest gas giant in the solar system. He is characterized by explaining things kindly and gently, and he is very smart. Nicknames: Smarty, Big Brother. Male. Moons: 115.

The second largest gas giant in the solar system. He has a fragile heart, is a crybaby, and has an innocent, child-like personality. Moons: 285–293. Nickname: Second Big Brother. Male. He takes great pride in his large and beautiful rings.

Uranus is the seventh planet and an ice giant in the solar system. He is prickly yet bright. Male. Moons: Titania, Oberon, Ariel, Umbriel, Miranda, and 29 others. His hobbies include writing in his diary and drawing. He has tilted white rings.

Neptune is the eighth planet and an ice giant in the solar system. Like Uranus, he is an ice giant and is Uranus's very close best friend. Due to his jelly-like surface and incredibly long orbital period, he can freely transform his body, but he often appears somewhat lacking and has a very poor memory. Male. Moons: Triton, Proteus, and 14 others.