Subaru enjoys making astronomical observations from childhood and is in the astronomy club by herself. She is indecisive and softhearted but has a strong trust in her friends.

She's a boyish girl but actually she loves cute stuff. She shows her feelings on her face through her actions although she always tries to hide them.

Itsuki is a mature, calm, and sweet girl. Surprisingly, she's a big eater and is very strong. Usually she doesn't push ahead her assertions but is more inquisitive than anyone.

She's the most active one among the girls and the moodmaker. She's not only a genius but also atheletic, and has perfect pitch.

She's a mysterious girl who's good at languages and understands the Pleiadian. She seems quite and somewhat cold but commits to studying and research to be helpful to everyone.

An alien called 'The President' who's asking Subaru and the others for help to gather the scattered fragments of the spaceship.

A boy who resides in an enigmatic greenhouse where Subaru gets lost and happens to go in. It feels like he is from somewhere outer space.